Wa e on sensing: A b eak h ough o objec i e e alua ion o dynamic
accommoda ion in accommoda i e dys unc ions
Jessica Gomes , Sand a F anco
*
Cen e o Physics o he Uni e si ies o Minho and Po o, Uni e si y o Minho, 4710-057, B aga, Po ugal
ARTICLE INFO
Keywo ds:
Wa e on sensing
Abe ome y
Ha mann-shack
Accommoda ion
Accommoda i e dys unc ions
ABSTRACT
The pu pose o his s udy was o use wa e on sensing as an objec i e me hod o de ec and assess dynamic
accommoda ion in subjec s wi h accommoda i e dys unc ions and symp oms ela ed o nea - ision asks.
Six y- h ee subjec s we e di ided in o con ol (N =18), symp oma ic wi hou any accommoda i e dys unc ion
(SWD) (N =18), in acili y o accommoda ion (INFA) (N =6), excess o accommoda ion (EA) (N =9), and
insu iciency o accommoda ion (INSA) (N =12) g oups. Accommoda ion was s imula ed in di e en cycles o
accommoda ion and disaccommoda ion while ocula abe a ions we e measu ed. Dynamic accommoda ion was
compu ed om ocula wa e on abe a ions and hen analysed, including esponse ime, peak eloci y, and
mic o luc ua ions.
Subjec s wi h accommoda i e dys unc ions showed al e a ions in accommoda i e esponses compa ed o he
con ol g oup, cha ac e ized by slowe and excessi e/ educed esponses, as well as an inc ease in accommo-
da i e mic o luc ua ions and di icul y in elaxing accommoda ion o di e en accommoda i e demands. The
SWD g oup showed signi ican changes compa ed o he con ol g oup, sugges ing accommoda i e p oblems no
p e iously de ec ed in clinical examina ions and explaining he symp oms epo ed by hese subjec s. The spe-
ci ic pa e ns o he cha ac e is ics o dynamic accommoda ion a e p esen ed o he di e en accommoda i e
dys unc ions.
The objec i e assessmen o dynamic accommoda ion using wa e on sensing, analysed o di e en
accommoda i e demands, p o ides a comp ehensi e app oach o he de ec ion and cha ac e isa ion o accom-
moda i e dys unc ions. This me hod enables he imp o emen o he p ecision o he diagnosis o accommo-
da i e dys unc ions and allows i s de ec ion in cases ha may no be de ec ed by cu en clinical examina ions. In
addi ion, his me hod may con ibu e o pe sonalized ea men planning, po en ially imp o ing pa ien ou -
comes in clinical p ac ice.
1. In oduc ion
Accommoda ion is a undamen al mechanism o he isual sys em
ha allows clea images on he e ina o objec s a di e en dis ances.
S a ic accommoda ion e e s o he accommoda i e esponse o an ob-
jec a a speci ic dis ance and ime, while dynamic accommoda ion in-
ol es an adjus men o he isual sys em o ocus objec s a a ying
dis ances and hei luc ua ions o e ime o a ce ain s imulus. This
p ocedu e is cha ac e ized by depending on he oculomo o sys em and
neu ological con ol signals igge ed by a blu ed e inal image [1,2].
P e ious au ho s epo ed a ia ions be ween dynamically and s a ically
eco ded accommoda i e esponses [3].
The e alua ion o dynamic accommoda ion may p o ide ex ensi e
in o ma ion, including la ency, esponse ime, eloci y, accele a ion,
and mic o luc ua ions o accommoda ion and disaccommoda ion [1,
4–8]. Since he isual sys em is cons an ly exposed o a ia ions in he
iewing condi ions and unde goes mic o luc ua ions e en wi h sus-
ained ocus [8], he assessmen o dynamic accommoda ion is close o
eal daily condi ions and may p o ide aluable insigh s beyond only
assessing s a ic accommoda ion, such as ampli ude and lag o accom-
moda ion, ob ained by he cu en clinical examina ions. The pa ame-
e s ob ained om dynamic accommoda ion con ibu e o a be e
unde s anding o he accommoda i e p ocess and may be pa icula ly
use ul in subjec s wi h accommoda i e diso de s.
Shack-Ha man wa e on senso s p o ide accu a e measu emen s
o he wa e on shape, and se e al s udies ha e shown i o be a eliable
* Co esponding au ho .
E-mail add esses: [email p o ec ed] (J. Gomes), [email p o ec ed] (S. F anco).
Con en s lis s a ailable a ScienceDi ec
Compu e s in Biology and Medicine
jou nal homepage: www.else ie .com/loca e/compbiomed
h ps://doi.o g/10.1016/j.compbiomed.2025.109718
Recei ed 4 No embe 2024; Recei ed in e ised o m 27 Decembe 2024; Accep ed 17 Janua y 2025
Compu e s in Biology and Medicine 186 (2025) 109718
A ailable online 22 Janua y 2025
0010-4825/© 2025 Published by Else ie L d.
me hod o analysing he accommoda i e esponse compu ed om
de ocus abe a ion [9–11]. Dynamic measu es o ocula accommoda ion
can be ob ained by aking measu emen s ac oss ime and o di e en
s imuli [12–14]. A p io s udy employed his app oach o con ol he
accommoda i e esponse du ing subjec i e e ac ion, demons a ing i s
eliabili y and u ili y [15].
Accommoda i e dys unc ions impac a signi ican numbe o in-
di iduals, esul ing in symp oms and posing pa icula challenges o
hose engaged in ex ended nea - ision asks [16,17]. Al hough accom-
moda i e dys unc ions ha e been clinically epo ed, hei unde lying
mechanisms emain la gely unexplo ed. Fu he mo e, he e is a lack o
s udies cha ac e izing in de ail he accommoda i e beha iou o hese
subjec s, i.e., he dynamic ea u es o accommoda ion. In addi ion, he
subjec i i y o he exams and he dissimila i y in he diagnos ic c i e ia
used make i di icul o de ec and diagnose e ec i ely. An objec i e
dynamic assessmen o accommoda ion may p o ide deepe in o ma ion
o cha ac e ise and unde s and he accommoda i e beha iou o sub-
jec s wi h accommoda i e dys unc ions, imp o ing hei diagnosis. The
pu pose o his s udy is o use wa e on sensing as a no el objec i e
me hod o assess and de ec accommoda i e p oblems and o cha ac-
e ise he dynamic accommoda i e p ope ies in hese subjec s.
2. Me hods
2.1. Pa icipan s
Pa icipan s we e ec ui ed h ough an email sen o all unde g ad-
ua e, mas e s and doc o al s uden s, as well as esea che s and p o-
esso s om all depa men s a he Uni e si y o Minho. To be eligible
o he s udy, indi iduals had o be heal hy and unde he age o 35,
excluding p esbyopes and p e-p esbyopes. The email explained he aims
o he s udy and ga e a b ie desc ip ion o he p ocedu es, explaining
ha hey consis ed o a habi ual eye exam wi h an addi ional exam o
assess he op ical quali y o he eye, all o which non-in asi e. Those
in e es ed in pa icipa ing p o ided hei email add ess so ha da a
collec ion could be scheduled. Pa icipan s we e encou aged o schedule
in he mo ning o a oid he e ec s o s ess om hei wo k/s udy day
and be o e pe o ming long isual asks. None o he pa icipan s had
any p io con ac wi h he sys em used o measu e ocula abe a ions.
The pa icipan s i s unde wen an eye examina ion, including
objec i e (s a ic e inoscopy wi h con ala e al ogging echnique o
con ol accommoda ion) and subjec i e e ac ion. The subjec i e
e ac ion s a ed om he alue o he objec i e e ac ion, and he
maximum plus lens o bes isual acui y was ound o each eye. The
assessmen o e ac i e e o was pe o med wi hou he use o cyclo-
plegia. P e ious s udies sugges ed ha he mos signi ican di e ences
be ween cycloplegic and non-cycloplegic e ac ion we e obse ed in
child en and o high hype opia [18,19]. A p e ious s udy also sug-
ges ed ha non-cycloplegic e ac ion using a con ala e al ogging
echnique is e ec i e as cycloplegic e ac ion o measu ing e ac i e
e o and has no clinical impac [20].
Binocula ision and accommoda ion we e also assessed. The
ampli ude o accommoda ion was measu ed by he Shea d me hod, he
lag o accommoda ion by he MEM (monocula es ima ed me hod)
e inoscopy, and he acili y o accommoda ion a nea ision wi h
lenses ±2.00D. The subjec s’ accommoda i e and binocula dys unc-
ions we e classi ied acco ding o he c i e ia o La a e al. [21], as
shown in Table 1, and hey ne e ecei ed any ea men o his con-
di ion. Bes -co ec ed isual acui y was 20/20 o be e , and subjec s
wi h binocula ision dys unc ions, his o y o ocula pa hology, ocula
su ge y, o hoke a ology, o use o medica ions ha could a ec he
isual sys em we e excluded. To de e mine whe he hey we e symp-
oma ic o asymp oma ic, he CISS su ey was adminis e ed o he
subjec s, and hey we e conside ed symp oma ic wi h a sco e highe
han o equal o 21 [22].
A e his examina ion, six y- h ee pa icipan s we e included in he
s udy and we e di ided in o ou g oups: a con ol g oup o asymp-
oma ic subjec s wi hou any accommoda i e dys unc ion (con ol); a
g oup o symp oma ic subjec s bu wi hou any accommoda i e
dys unc ion (SWD); a g oup wi h in acili y o accommoda ion (INFA); a
g oup wi h an excess o accommoda ion (EA); and a g oup wi h insu -
iciency o accommoda ion (INSA).
The s udy adhe ed o he ene s o he Decla a ion o Helsinki and
was app o ed by he E hical Subcommission o Li e and Heal h Science
o he Uni e si y o Minho (SECVS 029/2014 (ADENDA), July 2, 2019).
All subjec s signed an in o med consen wi h an explana ion o he
p ocedu es. This explana ion consis ed o a b ie desc ip ion o he
echnical p ocedu es o he exams.
2.2. Se -up and p ocedu e
An adap i e op ical sys em wi h an in-house Ha mann-Shack
abe ome e (Tho labs WF150-7AR) was used o assess in eal- ime
ocula abe a ions in he subjec ’s igh eye while inducing accommo-
da ion wi h nega i e lenses in he same eye. The con ala e al eye was
occluded using an eye pa ch o ensu e monocula iewing condi ions.
The powe s o he lenses used we e −1.00 D, −2.50 D, and −5.00 D. The
abe ome e had a esolu ion o 1280 ×1024 and 39 ×31, wi h lenses
wo king a a equency o 10 Hz. The powe o he supe luminescen
diode (SLD), used o gene a e he op ical beam, was 10
μ
W (L8414-04,
Table 1
Diagnos ic c i e ia o accommoda i e and binocula dys unc ions.
Accommoda i e Dys unc ions
In acili y o
accommoda ion
Excess o
accommoda ion
Insu iciency o
acommoda ion
Signals •Monocula
accommoda i e
acili y ≤6 cpm
and binocula ≤3
cpm
•PRA ≤1.25 D and
NRA ≤1.50 D
•Va iable VA
•Va iable s a ic
e inoscopy/
subjec i e
e ac ion
•Monocula
accommoda i e
acili y ≤6 cpm
wi h di icul y wi h
he lens +2.00 D
And wo o hese:
•Binocula
accommoda i e
acili y ≤3 cpm
wi h di icul y wi h
he lens +2.00 D
•MEM <+0.25 D
•NRA ≤1.50 D
•AA a leas 2.00 D
below 15−0.25 ×
age15−0.25 ×age
•Monocula
accommoda i e
acili y ≤6 cpm
wi h di icul y wi h
he lens −2.00 D
And wo o hese:
•Binocula
accommoda i e
acili y ≤3 cpm
wi h di icul y wi h
he lens −2.00 D
•MEM >+0.75 D
•PRA ≤1.25 D
Binocula dys unc ions
Con e gence
insu iciency
Con e gence
excess
Basic exopho ia
Signals •Exopho ia a
nea >6Δ
•PFV a nea
≤11/14/3
(blu /b eak/
eco e y)
•NPC >10 cm
And wo o hese:
•AC/A a io <3/1
•Fails BAF wi h
+2.00 D (≤3
cpm)
•MEM <+0.25 D
•PRA ≤1.50 D
•Esopho ia >2Δ
•NFV ≤8/16/7
(blu /b eak/
eco e y)
And wo o hese:
•AC/A >7/1
•Fails BAF wi h
−2.00 D (≤3
cpm)
•MEM >+0.75
D
•PRA ≤1.25 D
•Exopho ia o
app oxima ely o equal
magni ude a nea and
dis ance (wi hin 5 D)
•PFV <11/14/3 and <4/8/
5 (blu /b eak/ eco e y) a
nea and dis ance,
espec i ely
And wo o hese:
•No mal AC/A a io
•BAF <3 cpm
•MEM <0.25 D
•NRA <1.50 D
cpm: cycles/minu e; PRA: posi i e ela i e accommoda ion; NRA: nega i e
ela i e accommoda ion; VA: isual acui y; MEM: monocula es ima ed me hod;
AA: ampli ude o accommoda ion; PFV: posi i e usional e gence; NFV: nega-
i e usional e gence; NPC: nea poin o con e gence; BAF: binocula
accommoda i e acili y.
J. Gomes and S. F anco
Compu e s in Biology and Medicine 186 (2025) 109718
2
Hamama su, Shizuoka, Japan) a he eye and had a spec al maximum a
830 nm. The beam diame e wi hin he wa e on senso was app oxi-
ma ely 4 mm, wi h an e ec i e diame e o 2 mm used o abe a ions
measu emen . A schema ic ep esen a ion o he sys em is shown in
Fig. 1.
The subjec ’s eye was aligned wi h he sys em and s abilised using a
chin and o ehead suppo uni . The a ge consis ed o a whi e c oss on a
black backg ound co esponden o a isual acui y o 20/25 and simu-
la ed o be a a (≈6 m). The subjec s we e ins uc ed o keep i in ocus
as bes hey could. The subjec ’s e ac i e e o , including sphe e and
as igma ism, was ully co ec ed wi h lenses du ing he measu emen s.
This co ec ion was on he basis o he subjec i e e ac ion p e iously
de e mined.
Each subjec was exposed o di e en cycles o accommoda ion and
disaccommoda ion. Disaccommoda ion is he elaxa ion o he ocula
accommoda i e sys em a e a s imulus (when changing om nea o
a ), in ol ing he elaxa ion o he cilia y muscle and dec ease o he
lens powe [6,23]. Conside ing he dis ance o 20 mm om he lens o
he eye and he condi ions o he simula ed a a ge , he accommo-
da ion was s imula ed in he ollowing o de : 0.00 D → 1.00 D → 0.00 D
→ 2.45 D → 0.00 D → 4.73 D → 0.00 D. Each lens was placed in on o
he subjec ’s eye o app oxima ely 5 s, esul ing in app oxima ely 50
measu es o each accommoda i e s imulus.
2.3. Da a analysis
Accommoda ion esponse was calcula ed by he Ze nike second-
o de sphe ical de ocus e m and aking in o accoun he lens in on
o he subjec ’s eye used o s imula e accommoda ion by he o mula
[24]:
AR =Mi −M−Pl ×(1+d×M)×(1+d×Mi)
1−d×Pl ×(1+d×M),(5.6.1)
whe e AR is he accommoda ion esponse, Mi is he ini ial sphe ical
equi alen alue o he subjec , M is he sphe ical equi alen a each
ins an , Pl is he powe o he lens used o s imula e accommoda ion, and
d is he dis ance be ween he lens and he subjec ’s eye. The sphe ical
equi alen (M) was ob ained using he ollowing o mula [25]:
M=−4
3
√Z0
2
2,(5.6.2)
whe e Z0
2 ep esen s he de ocus e m and ep esen s he pupil adius.
Measu emen s we e aken and analysed o a pupil adius o 2.25 mm,
ensu ing ha all subjec s had a pupil size g ea e han o equal o his
alue.
Ini ial s a e e e s o he ini ial accommoda i e s a e o he subjec s
be o e being submi ed o accommoda i e s imuli and esidual accom-
moda ion is he accommoda ion emaining e en a e i has a emp ed
o shi i s ocus back o a es ing s a e ollowing an accommoda i e
s imulus.
The means we e calcula ed when accommoda ion was s abilised, i.e.
be ween he ime when he accommoda i e o disaccommoda i e
esponse eached 98 % o i s o al change and he end o he s imulus
[26].
The da a we e isually analysed, and any accommoda i e esponses
wi h andom pa e ns and blinks we e excluded om he analysis.
Acco ding o a p e ious s udy [27], he s a egy used o analyse
accommoda ion and disaccommoda ion esponses should be chosen o
each subjec o ob ain he mos accu a e analysis and he pa ame e s o
p ope ly cha ac e ise he accommoda ion and disaccommoda ion dy-
namics. The e o e, wo di e en models we e i ed o he AR o each
subjec , and he model ha bes i ed he o iginal da a was selec ed.
This was done by calcula ing he mean RMS e o ob ained be ween he
i ed unc ion and he o iginal da a.
The exponen ial model was gi en by he ollowing unc ion (Fig. 2):
Fig. 1. Schema ic ep esen a ion o he op ical sys em used o measu emen s.
J. Gomes and S. F anco
Compu e s in Biology and Medicine 186 (2025) 109718
3
Ac = 0±a⎛
⎝1−e−x
τ
⎞
⎠,(5.6.3)
whe e Ac is he AR a each momen in diop e s, 0 is he ini ial AR
(wi hou la ency) in diop e s, a ep esen s he ampli ude o he esponse
in diop e s, x is ime in seconds, and
τ
ep esen s he ime cons an . The
signal is posi i e o accommoda ion and nega i e o dis-
accommoda ion.
The Bol zmann sigmoidal model was de ined by he unc ion (Fig. 2):
Ac =A −Ai
1+e− (x−x0)
w+Ai,(5.6.4)
whe e x is he ime in seconds, A and Ai a e he ini ial and inal
asymp o ic alues, w is he wid h o he x alues be ween hese wo
asymp o es, and x0 is loca ed oughly a he cen e o w [27].
The esponse ime was de ined as he ime be ween he onse o he
s imulus s ep and 98 % o he o al change in accommoda ion when a
s able AR is eached [26].
Veloci y cu es we e ob ained by aking he i s de i a i e o he
i ed unc ion:
V(x)=
∂
Ac
∂
x,(5.6.4)
whe e V is he eloci y o accommoda ion.
The peak eloci y was ob ained by sol ing i when x=0 (Fig. 3) o
he exponen ial model. Fo he Bol zmann sigmoidal model, he peak
eloci y o accommoda ion o disaccommoda ion co esponds o he
maximum o minimum o he de i a i e unc ion, espec i ely (Fig. 3)
[27].
The oo mean squa e (RMS) de ia ion was used by se e al au ho s
o assess he magni ude o he accommoda i e mic o luc ua ions. This
pa ame e p o ides he mean le el o luc ua ion in diop es a ound he
a e age AR o e a de ined pe iod [28,29]. In his s udy, we also used his
me ic o assess he accommoda i e mic o luc ua ions, and i was
compu ed using he ollowing o mula:
RMSde ia ion =
1
n∑(xi−x)2
√,(5.6.5)
whe e n is he numbe o AR aken, xi is each indi idual AR, and x is he
a e age AR.
All hese analyses we e ca ied ou using an algo i hm de eloped in
e sion 12.3 o he Wol am Ma hema ica so wa e (Wol am Resea ch,
Inc., Champaign, IL (2021)). S a is ical analysis was pe o med using
IBM SPSS so wa e, e sion 29.0.0.0 (IBM Co p., A monk, NY). The
no mali y o he da a was es ed using he Shapi o-Wilk es . To compa e
he means be ween g oups, one-way ANOVA was used o pa ame ic
da a and K uskal-Wallis o non-pa ame ic da a. To compa e he di -
e ences be ween he ini ial accommoda i e s a e and he subsequen
s imuli, ANOVA o epea ed measu es was used o pa ame ic da a,
and F iedman’s es o non-pa ame ic da a. Bon e oni co ec ion was
pe o med o mul iple compa isons.
3. Resul s
In his s udy, 63 eyes o 63 subjec s we e en olled and di ided in o
di e en g oups acco ding o hei accommoda i e dys unc ion and
symp oma ology. The numbe o subjec s in each g oup, hei mean age,
mean sphe ical equi alen (SE), he esul s o he accommoda i e exams
(ampli ude o accommoda ion (AA), lag o accommoda ion (LA), and
acili y o accommoda ion (FA)) pe o med a he ini ial eye examina-
ion, and he mean CISS sco e a e shown in Table 2.
Age and sphe ical equi alen we e simila in all g oups, wi h no
s a is ically signi ican di e ences be ween hem (p =0.27 o age and p
=0.54 o sphe ical equi alen ). Conce ning he accommoda i e exams
a he ini ial eye examina ion: AA was signi ican ly lowe in subjec s
wi h INSA han in he con ol g oup (p <0.001); LA was signi ican ly
lowe in subjec s wi h EA and highe in subjec s wi h INSA han in he
con ol g oup (p =0.02 o bo h); and FA was signi ican ly lowe in
subjec s wi h INFA (p <0.001), EA (p <0.001), and INSA (p <0.001)
han in he con ol g oup. The CISS sco e was signi ican ly highe in he
INSA (p =0.03) and SWD (p <0.001) g oups. The mos common
symp om epo ed by he subjec s o he SWD g oup was “Eyes i ed”
while eading/doing close wo k, ollowed by “Eyes hu ”, “Headache”,
“Di icul y main aining a en ion/concen a ion”, “Uncom o able” and
“T ouble emembe ing “. The o he symp oms had an indi idual sco e
lowe han 2.00.
3.1. Accommoda i e esponse
The dynamic accommoda i e and disaccommoda i e esponses o e
ime ob ained om wa e on abe ome y o di e en s imuli a e
shown in Fig. 4 and he mean alues o accommoda i e esponse and he
esidual accommoda ion o each g oup a e shown in Table 3. As
Fig. 2. The Bol zmann sigmoidal unc ion ( ed) and he exponen ial unc ion
(blue) i ed o he expe imen al da a poin s (black) o accommoda ion o one
subjec o 1.00D o accommoda i e s imulus. G ey cu es show smoo hed
in e pola ion o he accommoda i e esponses. (Fo in e p e a ion o he e -
e ences o colou in his igu e legend, he eade is e e ed o he Web e sion
o his a icle.)
Fig. 3. Accommoda ion eloci y cu es when he Bol zmann sigmoidal ( ed)
and he exponen ial (blue) unc ions we e i ed o he expe imen al da a o one
subjec o 1.00D o accommoda i e s imulus. (Fo in e p e a ion o he e e -
ences o colou in his igu e legend, he eade is e e ed o he Web e sion o
his a icle.)
J. Gomes and S. F anco
Compu e s in Biology and Medicine 186 (2025) 109718
4
expec ed, all subjec s showed an inc ease in accommoda i e esponse as
he accommoda i e s imulus inc eased.
The con ol g oup p esen ed an accommoda i e esponse close o he
alues o he s imuli (Fig. 4). On he o he hand, a mean lead o ac-
commoda ion was obse ed in he INFA g oup o he 2.45 D and 4.73 D
s imuli, i.e., he mean accommoda i e esponse was highe han he
s imuli, bu i was no signi ican ly highe han he con ol g oup
(1.00D, p =0.57; 2.45D, p =0.07; 4.73D, p =0.61). The EA g oup also
showed a mean lead o accommoda ion o all s imuli, and he accom-
moda i e esponse was signi ican ly highe han he con ol g oup o
he 1.00D (p =0.049), 2.45D (p =0.04), and 4.73D (p <0.01) s imuli.
On he o he hand, i is possible o obse e a lowe accommoda i e
esponse in he INSA g oup, which was s a is ically signi ican ly lowe
han in he con ol g oup o he 4.73D s imulus (p =0.02) bu no o
he 1.00D (p =0.07) and 2.45D (p =0.98) s imuli. The SWD g oup had a
simila accommoda i e esponse o he con ol g oup o all accommo-
da i e s imuli (1.00D, p =0.35; 2.45D, p =0.56; 4.73D, p =0.61).
Table 2
Cha ac e is ics (mean ±s anda d de ia ion) o he subjec s in each g oup.
N Age (yea s) SE (D) AA (D) LA (D) FA (cpm) CISS Sco e
Con ol 18 23.9 ±3.05 0.02 ±0.30 9.60 ±1.01 0.57 ±0.22 14.33 ±4.38 12.56 ±4.33
SWD 18 23.2 ±3.28* −0.72 ±1.61* 10.01 ±2.11* 0.56 ±0.20* 13.67 ±4.73* 27.33 ±2.73†
INFA 6 24.4 ±5.03* −0.29 ±1.32* 8.04 ±2.64* 0.63 ±0.38* 3.50 ±1.97†19.00 ±12.26*
EA 9 22.9 ±3.37* 0.32 ±0.43* 8.75 ±1.78* 0.38 ±0.18†1.11 ±2.20†12.22 ±6.53*
INSA 12 21.3 ±4.13* −0.52 ±2.81* 5.71 ±1.29†0.92 ±0.33†7.77 ±4.51†20.5 ±11.39¤
p*>0.05 *>0.05 *>0.05; †<0.001 *>0.05; †0.02 *>0.05; †<0.001 *>0.05; †<0.001; ¤0.03
*, †, ¤ Compa ison o he con ol g oup.
N: numbe o subjec s; cpm: cycles pe minu e; INFA: In acili y o accommoda ion; EA: Excess o accommoda ion; INSA: Insu iciency o accommoda ion; SWD:
Symp oma ic wi hou dys unc ion.
The ±e o s indica e he s anda d de ia ion om he mean.
Fig. 4. Accommoda i e esponse (black line) o e ime o he di e en accommoda i e s imuli ( ed line) o he subjec s o he di e en g oups: con ol, INFA, EA,
INSA, and SWD.
* S a is ically signi ican di e ence compa ed o he con ol g oup; ɸ S a is ically signi ican di e ence compa ed o he ini ial s a e. (Fo in e p e a ion o he
e e ences o colou in his igu e legend, he eade is e e ed o he Web e sion o his a icle.)
J. Gomes and S. F anco
Compu e s in Biology and Medicine 186 (2025) 109718
5
3.2. Residual accommoda ion
The subjec s o he con ol g oup we e able o elax accommoda ion
a e emo ing he s imuli and e u n o hei ini ial s a e, showing a
esidual accommoda ion no signi ican ly di e en o he ini ial s a e
(a e 1.00D, p =0.72; 2.45D, p =0.84; 4.73D, p =0.41) (Table 2). This
beha iou was no ound in he o he g oups. The subjec s wi h INFA
we e no able o elax he accommoda ion a e he 4.73D s imulus,
main aining a signi ican esidual accommoda ion when compa ed o
he ini ial s a e (1.00D, p =0.29; 2.45D, p =0.35; 4.73D, p =0.02). The
EA g oup had a esidual accommoda ion signi ican ly highe han he
ini ial s a e a e emo ing all s imuli (1.00D, p =0.04; 2.45D, p =0.03;
4.73D, p =0.01). The subjec s wi h INSA we e also unable o elax ac-
commoda ion a e emo ing he 1.00D and 2.45D s imuli, wi h alues
o esidual accommoda ion signi ican ly highe han he ini ial s a e
(1.00D, p =0.01; 2.45D, p =0.03; 4.73D, p =0.10). In he SWD g oup,
esidual accommoda ion was signi ican ly highe han he ini ial s a e
a e he 1.00D (p =0.03), 2.45D (p =0.01), and 4.73D (p =0.03)
s imuli we e emo ed.
3.3. Mic o luc ua ions o accommoda i e esponse and esidual
accommoda ion
The mic o luc ua ions o accommoda ion we e assessed by RMS
de ia ion. Fig. 5 shows he di e ences be ween i s alue a each
accommoda i e s a e and he ini ial alue. The con ol, EA, and INFA
g oups show no signi ican changes in mic o luc ua ions be ween he
ini ial s a e and du ing he 1.00D (con ol, p =0.54; EA, p =0.54; INFA,
p =0.70), 2.45D (con ol, p =0.54; EA, p =0.08; INFA, p =0.25) and
4.73D (con ol, p =0.15; EA, p =0.66; INFA, p =0.44) s imuli. On he
o he hand, he INSA g oup had a signi ican inc ease in mic o-
luc ua ions du ing he 1.00D (p =0.001), 2.45D (p =0.03), and 4.73D
(p =0.03) accommoda i e s imuli. The same was obse ed in he SWD
g oup, wi h a signi ican inc ease du ing he 1.00D (p =0.03), 2.45D (p
=0.048), and 4.73D (p =0.047) accommoda i e s imuli.
The mic o luc ua ions o esidual accommoda ion (Fig. 5) o he
con ol and EA g oups showed no signi ican di e ences be ween he
ini ial s a e and a e emo ing he 1.00D (con ol, p =0.54; EA, p =
0.46), 2.45D (con ol, p =0.84; EA, p =0.31), and 4.73D (con ol, p =
0.68; EA, p =0.31) s imuli. The INFA g oup had signi ican ly highe
mic o luc ua ions a e he 2.45D (p =0.04) s imulus was emo ed
when compa ed o he ini ial s a e, bu no a e he 1.00D (p =0.50)
and 4.73D (p =0.83) s imuli. The INSA g oup showed signi ican ly
highe alues a e emo ing he 2.45D (p =0.01) and 4.73D (p =0.03)
s imuli compa ed o he ini ial s a e, bu no a e he 1.00D (p =0.18)
s imulus. The SWD g oup had signi ican ly highe alues a e he 1.00D
(p =0.03), 2.45D (p =0.03), and 4.73D (p =0.02) s imuli we e
emo ed compa ed o he ini ial s a e.
3.4. Accommoda i e and disaccommoda i e esponse imes
Accommoda i e and disaccommoda i e esponse imes o each
g oup a e shown in Table 4. Di e ences in esponse ime we e obse ed
be ween he con ol g oup and he INFA, EA, INSA, and SWD g oups o
some accommoda i e condi ions. The INFA g oup had a signi ican ly
slowe accommoda i e esponse han he con ol g oup a 2.40D (p =
0.03) and 4.73D (p =0.045) accommoda i e s imuli, bu no a 1.00D
(p =0.81). SWD also had a slowe accommoda i e esponse o he
1.00D (p =0.046) and 2.45D (p =0.048) accommoda i e s imuli, bu no
signi ican di e ences o he 4.73D s imulus (p =0.76). On he o he
hand, he EA g oup had a signi ican ly as e accommoda i e esponse a
1.00D o accommoda i e s imulus (p =0.045), bu wi h no signi ican
di e ences a 2.45D (p =0.79) and 4.73D (p =0.99). The INSA g oup
had no signi ican di e ences compa ed o he con ol g oup a any
s imulus (1.00D, p =0.56; 2.45D, p =0.09; 4.73D, p =0.99).
Rega ding disaccommoda ion esponse, he INFA g oup had slowe
disaccommoda ion han he con ol g oup a e he 1.00D (p =0.03) and
2.40D (p =0.01) s imuli, bu no signi ican di e ences a e 4.73D (p =
0.85). On he o he hand, he EA g oup showed signi ican di e ences
only a e he 4.73D s imulus (1.00D, p =0.89; 2.45D, p =0.99; 4.73D,
p =0.048). The INSA g oup had a signi ican ly slowe dis-
accommoda ion only a e he 2.45D s imulus (1.00D, p =0.68; 2.45D,
p =0.02; 4.73D, p =0.95), and he SWD g oup a e he 1.00D s imulus
(1.00D, p =0.048; 2.45D, p =0.51; 4.73D, p =0.63).
3.5. Peak eloci y o accommoda i e and disaccommoda i e esponses
Table 5 shows he peak eloci y o accommoda i e and dis-
accommoda i e esponses o he 1.00D, 2.45D, and 4.73D s imuli. The
esul s show ha he peak eloci y o accommoda i e and dis-
accommoda i e esponses changes signi ican ly be ween he INFA, EA,
INSA, and SWD g oups and he con ol g oup o some le els o
accommoda i e and disaccommoda i e s imuli. The INFA g oup shows a
signi ican ly lowe peak eloci y han he con ol g oup a 4.73D
Table 3
Mean and s anda d de ia ion o accommoda ion and esidual accommoda ion
alues o all g oups.
Accommoda i e esponse (D) Residual accommoda ion (D)
AS (D) 1.00 2.45 4.73 0.00
(1.00)
0.00
(2.45)
0.00
(4.73)
Con ol 0.89 ±
0.52
2.08 ±
0.82
4.85 ±
1.10
0.16 ±
0.38ɣ
0.01 ±
0.58ɣ
0.16 ±
0.26ɣ
INFA 0.98 ±
0.12*
2.74 ±
0.33*
5.50 ±
1.64*
0.24 ±
0.18ɣ
0.16 ±
0.34ɣ
0.91 ±
0.20ɸ
EA 1.40 ±
0.13†
2.70 ±
0.50†
5.59 ±
1.36†
0.25 ±
0.21ɸ
0.28 ±
0.23ɸ
0.38 ±
0.02¤
INSA 0.59 ±
0.66*
2.02 ±
0.92*
3.97 ±
0.86¢
0.38 ±
0.35¤
0.34 ±
0.32ɸ
0.25 ±
0.16ɣ
SWD 0.75 ±
0.28*
2.30 ±
0.71*
4.65 ±
0.55*
0.21 ±
0.11¥
0.32 ±
0.20¤
0.50 ±
0.19¥
p*>0.05;
†0.049
*>0.05;
†0.04
*>0.05;
†0.01; ¢
0.02
ɣ>0.05;
ɸ0.04;
¤0.01;
¥0.03
ɣ>0.05;
ɸ0.03;
¤0.01
ɣ>0.05;
ɸ0.02;
¤0.01; ¥
0.03
*; †; ¢ compa ison o he con ol g oup.
ɣ; ɸ; ¤; ¥ compa ison o he ini ial s a e.
AS: Accommoda i e s imulus; INFA: In acili y o accommoda ion; EA: Excess o
accommoda ion; INSA: Insu iciency o accommoda ion; SWD: Symp oma ic
wi hou dys unc ion.
The ±e o s indica e he s anda d de ia ion om he mean.
Fig. 5. Di e ences in RMS de ia ion o mic o luc ua ions be ween he
accommoda i e esponse and he esidual accommoda ion and he ini ial s a e.
E o ba s a e he con idence in e als o 95 %. p- alues ep esen s a is ically
signi ican di e ences be ween he alue o each s imulus and he ini ial alue.
J. Gomes and S. F anco
Compu e s in Biology and Medicine 186 (2025) 109718
6
accommoda i e s imulus (p =0.048), indica ing a limi a ion o hese
subjec s o achie e high eloci ies o high accommoda i e s imuli. The
AE g oup achie ed high eloci ies o accommoda i e esponse, wi h
signi ican ly highe alues o he 1.00D s imulus (p =0.046), whe eas
i was di icul o achie e high eloci ies o disaccommoda ion a e he
2.45D (p =0.03) and 4.73D (p =0.04) s imuli. The INSA g oup shows
signi ican ly lowe peak eloci y o accommoda i e esponse a 4.73D
s imulus (p =0.04) and in disaccommoda i e esponse a e he 2.45D
s imulus (p =0.048). The SWD g oup also had signi ican ly lowe peak
eloci ies o accommoda i e esponse a 1.00D (p =0.04) and 4.73D (p
=0.02) and in disaccommoda i e esponse a e he 4.73D s imulus (p
=0.047).
The indings ela ed o accommoda i e and disaccommoda i e e-
sponses, esidual accommoda ion, and hei mic o luc ua ions, esponse
imes, and peak eloci ies in each g oup o subjec s we e summa ized
and shown in Table 6. These signals a e based on s a is ically signi ican
di e ences ound compa ed o hei ini ial s a e and he con ol g oup
and show speci ic pa e ns o he cha ac e is ics o dynamic
accommoda ion and disaccommoda ion associa ed wi h each ype o
diso de .
4. Discussion
In his s udy, wa e on sensing was used o objec i ely assess he
dynamic accommoda ion o subjec s wi h accommoda i e dys unc ions
(INFA, INSA, and EA) as well as subjec s who expe ience symp oms
ela ed o nea ision asks bu who ha e no been diagnosed wi h any
accommoda i e dys unc ion (SWD). The la e g oup p ima ily epo ed
complain s such as “Eyes i ed” while eading/doing close wo k, ol-
lowed by “Eyes hu ”, “Headache”, “Di icul y main aining a en ion/
concen a ion”, “Uncom o able” and “T ouble emembe ing“, as
de ailed in he esul s sec ion. P e ious s udies ha e iden i ied hese
isual symp oms as ac o s ha can signi ican ly impac daily li e and
diminish bo h academic and p o essional pe o mance [30,31].
Accommoda i e and disaccommoda i e esponses we e assessed o
a ious cycles o accommoda ion and disaccommoda ion s imuli,
Table 4
Mean and s anda d de ia ion o accommoda i e and disaccommoda i e esponse imes o he di e en cycles o accommoda ion and disaccommoda ion o he
con ol, INFA, AE, INSA, and SWD g oups.
Response ime (ms)
Accommoda i e esponse Disaccommoda i e esponse
Accommoda i e s imulus (D) 1.00 2.45 4.73 0.00 (1.00) 0.00 (2.45) 0.00 (4.73)
Con ol 708 ±194 456 ±273 504 ±46 933 ±554 535 ±251 450 ±148
INFA 700 ±560* 698 ±161†1453 ±154†2170 ±316†2821 ±425†501 ±335*
EA 445 ±149†376 ±162* 631 ±211* 769 ±712* 1011 ±428* 1170 ±200†
INSA 1000 ±309* 535 ±339* 483 ±241* 573 ±354* 2220 ±501¤712 ±429*
SWD 1042 ±274¤926 ±355¤494 ±275* 2771 ±568¤1009 ±548* 635 ±228*
p*>0.05; †0.045; ¤0.046 *>0.05; †0.03; ¤0.048 *>0.05; †0.045 *>0.05; †0.03; ¤0.048 *>0.05; †0.01; ¤0.02 *>0.05; †0.048
*; †compa ison wi h he con ol g oup.
The ±e o s indica e he s anda d de ia ion om he mean.
Table 5
Mean peak eloci y o accommoda i e and disaccommoda i e esponses o he 1.00D, 2.45D, and 4.73D accommoda i e s imuli.
Peak eloci y (D/s)
Accommoda i e esponse Disaccommoda i e esponse
Accommoda i e s imulus (D) 1.00 2.45 4.73 0.00 (1.00) 0.00 (2.45) 0.00 (4.73)
Con ol 5.47 ±1.75 13.24 ±1.69 13.68 ±1.20 1.63 ±1.24 8.93 ±1.26 12.32 ±0.40
INFA 4.33 ±0.62 14.12 ±1.02 9.51 ±0.99* 2.01 ±0.65 8.19 ±2.02 11.03 ±2.01
AE 13.58 ±2.10* 15.77 ±2.95 10.60 ±3.31 12.00 ±0.12 6.90 ±0.25* 5.99 ±1.54*
INSA 2.39 ±1.55 9.29 ±2.97 10.84 ±1.05†5.14 ±3.00 4.30 ±2.50†13.16 ±1.85
SWD 1.84 ±0.52†13.39 ±1.39 6.70 ±0.22¢ 1.36 ±0.40 9.42 ±1.89 9.85 ±0.98†
p*0.046; †0.04 >0.05 *0.048; †0.04; ¢0.02 >0.05 *0.03; †0.048 *0.04; †0.047
*; †; ¢ s a is ically signi ican compa ed o he con ol g oup.
The ±e o s indica e he s anda d de ia ion om he mean.
Table 6
Signals o dynamic accommoda ion ound in subjec s wi h INFA, AE, INSA and SWD. Ini ial s a e e e s o he ini ial elaxed s a e be o e he s imuli.
INFA EA INSA SWD
Signals Accommoda i e
esponse
Wi hou signi ican
changes
↑ con ol and s imuli ↓ con ol and s imuli Wi hou signi ican
changes
Residual
accommoda ion
↑ han ini ial s a e ↑ han ini ial s a e ↑ han ini ial s a e ↑ han ini ial s a e
Mic o luc ua ions Accommoda i e
esponse
Wi hou signi ican
changes
Wi hou signi ican
changes
↑ han ini ial s a e ↑ han ini ial s a e
Residual
accommoda ion
↑ han ini ial s a e Wi hou signi ican
changes
↑ han ini ial s a e ↑ han ini ial s a e
AR ime Accommoda i e
esponse
↑ con ol ↓ con ol Wi hou signi ican
changes
↑ con ol
Residual
accommoda ion
↑ con ol ↑ con ol ↑ con ol ↑ con ol
Peak eloci y Accommoda i e
esponse
↓ con ol ↑ con ol ↓ con ol ↓ con ol
Residual
accommoda ion
Wi hou signi ican
changes
↓ con ol ↓ con ol ↓ con ol
J. Gomes and S. F anco
Compu e s in Biology and Medicine 186 (2025) 109718
7
e ealing cha ac e is ics dis inc om hose o he con ol g oup and
signi ican al e a ions compa ed o hei ini ial s a e.
Subjec s wi h INFA had signi ican ly slowe accommoda i e e-
sponses o 2.45D and 4.73D s imuli and ook mo e ime o elax ac-
commoda ion and s abilize i a e 1.00D and 2.45D s imuli han he
con ol g oup. Fo he 4.73D s imulus, hese subjec s we e unable o
comple ely elax accommoda ion, esul ing in a esidual accommoda-
ion ha was signi ican ly highe han he ini ial alue and he alue o
he con ol g oup. This is o be expec ed in subjec s who usually ha e
mo e di icul y wi h he posi i e lens in he lippe es . Du ing dis-
accommoda i e esponse a e his s imulus, a s able alue was achie ed
in a sho e ime, despi e incomple e elaxa ion o accommoda ion,
which explains he non-s a is ically signi ican di e ence in he esponse
ime o his s imulus. A p e ious s udy shows ha ime o dis-
accommoda ion may also be a p edic o o accommoda i e acili y [32].
Howe e , i is impo an o check ha he subjec s ac ually each hei
s a e o accommoda ion elaxa ion.
INFA is usually diagnosed based on he accommoda i e acili y es ,
which assesses only a a and one demand a nea . The me hod we
p esen ed no only p o ides he esponse imes bu also allows obse -
a ion o he acili y o accommoda ion o addi ional demands. This is
e y impo an o INFA, as i in ol es di icul y in changing ocus
quickly and accu a ely ac oss di e en demands, which could no be
ully assessed using adi ional me hods and he me hod we p opose
p o ides his no el ad an age. The peak eloci y o 4.73D also in-
dica es ha hese subjec s canno each high eloci ies o accommoda-
i e esponse o high s imuli. The signi ican inc ease in
mic o luc ua ions obse ed in he esidual accommoda ion a e he
2.45D s imulus e eals an inc ease in accommoda i e ins abili y. This
may explain he in e mi en ocusing some imes epo ed by hese
subjec s du ing he accommoda i e acili y es wi h he +2.00D lens a
nea ision, which may lead o e oneous esul s i he pa ien conside s
i as “clea ” despi e no icing uns able cla i y. They may ha e uns able
accommoda ion and as a esul may show a highe accommoda i e a-
cili y han i ac ually is.
Fo he EA g oup, he excessi e accommoda i e esponse and e-
sidual accommoda ion o all s imuli a e no able. These subjec s no only
accommoda ed mo e han he s imuli equi ed bu we e also unable o
elax accommoda ion o i s ini ial alue a e s imula ion. This is ex-
pec ed, as subjec s wi h EA a e cha ac e ized by p esen ing leads o
accommoda ion. The me hod p esen ed allows us o obse e ha he EA
is cha ac e ized by as accommoda i e esponses, eaching high e-
loci ies, bu slowe disaccommoda i e esponses and di icul y in
elaxing accommoda ion, wi h disaccommoda ion becoming slowe as
he s imulus inc eases. Subjec s wi h EA ha e accommoda i e esponses
highe han he expec ed alues o a ious accommoda i e demands,
which canno be obse ed in he clinical exams, which a e only pe -
o med o 2.50D demand. Fu he mo e, subjec s wi h EA in he ea ly
s ages may only ha e di icul y elaxing hei accommoda ion a e
highe s imuli (mo e han 2.50D), as he di e ences ound we e p o-
nounced o highe s imuli. The me hod we p esen is a new way o
de ec ing accommoda i e esponses ha a e highe han expec ed o
di e en accommoda i e demands, which is impo an o subjec s who
may p esen leads o accommoda ion o dis ances close o a he han
40 cm. On he o he hand, he mic o luc ua ions o accommoda ion do
no seem o be a ec ed by EA.
The INSA g oup had he lowes accommoda i e esponse o all
s imuli, being signi ican ly lowe han he con ol g oup o he 4.73D
s imulus. This is expec ed, as subjec s wi h INSA ha e lowe ampli ude
o accommoda ion. Gi en hei young age, i was expec ed o ind no
signi ican di e ences o low s imuli e en wi h INSA. Howe e , a e
he 1.00D and 2.45D s imuli, hey we e unable o ully elax hei ac-
commoda ion, showing signi ican esidual accommoda ion compa ed
o he ini ial alue. Con a y o p e ious s udies using clinical exami-
na ions, in which he −2.00D lens was ound o be mo e di icul in he
nea - ision accommoda i e acili y es , we obse ed ha hey also ha e
di icul y in elaxing accommoda ion, likely due o he excessi e e o
made by hese subjec s o keep he a ge in ocus. This is pa icula ly
e iden a e he 2.45D s imulus. This highligh s how dynamic accom-
moda ion assessmen can e eal elaxa ion di icul ies no ypically
de ec ed in he cu en clinical exams. These subjec s we e also unable
o achie e high eloci ies o accommoda ion and disaccommoda ion.
The obse ed signi ican inc ease in mic o luc ua ions o accommoda-
ion o all accommoda i e s imuli is p obably due o hei di icul y in
accommoda ing, leading o g ea e ins abili y in he accommoda i e
esponse, which is also obse ed a e he highes s imulus (4.73D). A
p e ious s udy [33] indica es ha mic o luc ua ions o accommoda ion
a e mo e p onounced in indi iduals wi h hinne cilia y bodies. Gi en
ha subjec s wi h accommoda i e dys unc ions exhibi inc eased
mic o luc ua ions du ing accommoda ion, he hickness o he cilia y
body may be ela ed o he de elopmen o some accommoda i e
dys unc ions.
The changes obse ed in dynamic accommoda ion a e pa icula ly
in e es ing in he SWD g oup. These subjec s had no mal clinical ex-
amina ions bu epo ed symp oms ela ed o nea asks, wi h a CISS
sco e highe han 21, which was signi ican ly highe han he con ol
g oup. When dynamic accommoda ion is analysed o he di e en cy-
cles o accommoda ion and disaccommoda ion, hese subjec s show
di icul y o disaccommoda e, wi h simila beha iou obse ed in sub-
jec s wi h accommoda i e dys unc ions. Thei esidual accommoda ion
was signi ican ly highe han bo h he ini ial alues and hose o he
con ol g oup. I hese subjec s a e on he e ge o de eloping an
accommoda i e dys unc ion, some o hem could p esen an accom-
moda i e esponse sligh ly highe and lowe han he s imuli ( o 1.00D,
2.45D, and 4.73D) and han he con ol g oup, esul ing in an a e age
close o he s imulus, which could explain hei non-signi ican di e -
ence wi h he con ol g oup. In addi ion, hei esponse imes we e
slowe han hose o he con ol g oup, wi h peak eloci ies eaching
lowe alues o ce ain demands. Fu he mo e, he signi ican inc ease
in accommoda i e mic o luc ua ions indica es ins abili y in he
accommoda i e esponse du ing all s imuli and in he esidual accom-
moda ion a e he s imuli a e emo ed. These no el insigh s p o ides a
po en ial explana ion o he symp oms epo ed by hese subjec s,
which a e e y common in hose who spend a lo o ime in nea ision
[34,35].
Ano he inding is he non-linea i y o he peak eloci y wi h he
accommoda i e esponse ampli ude in he subjec s wi h accommoda i e
dys unc ions and SWD, obse ed by p e ious s udies [6]. Peak eloci ies
a e in luenced by he s a ing poin o he esponse [6,36], which a ied
o disaccommoda ion in ou s udy. This a iabili y, along wi h he
p esence o dys unc ional accommoda i e esponses, may explain he
non-linea i y o peak eloci y.
The assessmen o dynamic accommoda ion allows eal- ime moni-
o ing o he accommoda i e beha iou when changing be ween
di e en dis ances. This p o ides a close ep esen a ion o he accom-
moda i e pe o mance in e e yday si ua ions compa ed o s a ic mea-
su emen s and gi es us mo e de ailed in o ma ion abou he
accommoda i e esponse. Acco ding o p e ious s udies [37,38], many
subjec s pe o m nea ision asks a dis ances sho e han 40 cm, so i is
impo an o analyse he accommoda i e esponse a dis ances beyond
his, which is he only dis ance analysed in clinical exams.
Some accommoda i e diso de s may no be appa en h ough s a ic
es ing, bu he assessmen o dynamic accommoda ion using he
me hod we p esen can e eal issues ha may o he wise be missed.
Addi ionally, wa e on measu emen p o ides objec i e and quan i a-
i e da a, educing eliance on subjec i e pa ien esponses. This me hod
may be a new way o imp o e he diagnosis o accommoda i e dys-
unc ions and allow o hei de ec ion a ea ly s ages, pe haps be o e
symp oms mani es . De ailed in o ma ion om dynamic accommoda-
ion e alua ion may assis eye ca e p o essionals in selec ing he mos
app op ia e ea men o pa ien s, o ins ance, o educe he accom-
moda i e esponse, imp o e he esponse ime, o educe he
J. Gomes and S. F anco
Compu e s in Biology and Medicine 186 (2025) 109718
8
mic o luc ua ions o accommoda ion, ailo ed o each pa ien ’s speci ic
accommoda i e issues. Mo eo e , i may also help p o essionals ailo
ea men plans, such as ision he apy plans, o mo e e ec i e ollow-
up. The esul s sugges a comme cial and clinical po en ial o his
me hod o assis and imp o e he diagnosis and ollow-up o such
condi ions.
The s udy also has impo an limi a ions ha also should be dis-
cussed. I is impo an o no e ha he measu emen s we e made unde
monocula a he han binocula iewing condi ions. Pe o ming he
measu emen s monocula ly would miss he e ec o con e gence. Ac-
co ding o a p e ious s udy he objec i e measu emen s o accommo-
da ion using he Shack-Ha mann wa e on senso may show highe
alues compa ed o he monocula iewing condi ion [39]. This could be
a limi a ion o ou esul s. Howe e , his di e ence be ween monocula
and binocula accommoda ion is pa icula ly p oblema ic in exopho ic
and esopho ic subjec s [40], which we e no included in ou s udy.
Mo eo e , in clinical p ac ice, he ampli ude and acili y o accommo-
da ion a e also usually measu ed monocula ly. This issue migh also be
mi iga ed i we conside ha his e ec is p esen in all subjec s,
including he con ol g oup.
Ano he limi a ion o ou s udy is he sample size o some g oups,
especially he INFA g oup. I is impo an o emphasise ha he esul s o
his g oup in pa icula should be ca e ully analysed when ex ended o
he gene al popula ion and should be conside ed as p elimina y esul s.
Fu u e s udies should use la ge and mo e balanced samples o subjec s
wi h accommoda i e dys unc ion o inc ease s a is ical powe , imp o e
eliabili y and inc ease he alida ion o he esul s.
The pa icipan s nea wo k habi s we e a missing in o ma ion in ou
s udy. Fu u e s udies should collec his da a o in es iga e he ela-
ionship be ween nea wo k habi s, symp oms and changes in he
cha ac e is ics o he dynamic accommoda i e esponse. This could
include assessing dynamic accommoda ion in subjec s wi h di e en
nea wo k habi s, o assessing i a e asks pe o med a di e en dis-
ances and wi h di e en demands. Such esea ch may p o ide insigh s
in o how speci ic wo k habi s a ec accommoda i e unc ion and help o
iden i y ea ly ma ke s ha may lead o speci ic accommoda i e dys-
unc ions and symp oms.
We also sugges o ca y ou longi udinal s udies o in es iga e
whe he dynamic accommoda i e assessmen me hods de ec ea ly signs
o accommoda i e dys unc ions be o e symp oms become appa en , i.e.
which subjec s a e a isk o de eloping accommoda i e dys unc ion and
ela ed symp oms, and how hese indings co ela e wi h he onse o
clinical symp oms. Assessing hese accommoda i e pa ame e s and
ollowing subjec s o e ime o obse e which o hem de elop hese
issues would be in e es ing o u he explo a ion o his opic. Ano he
sugges ion migh be o ollow-up pa ien s o e ime and obse e he
e ec s o ailo ed in e en ions, such as ision he apy o op ical co -
ec ions, on hese dynamic accommoda i e pa ame e s.
O he me hods o con inuous measu emen o he accommoda i e
esponse, such as con inuous pho o e ac ion, should be explo ed o he
same applicabili y.
CRediT au ho ship con ibu ion s a emen
Jessica Gomes: W i ing – o iginal d a , Valida ion, Me hodology,
In es iga ion, Funding acquisi ion, Fo mal analysis. Sand a F anco:
W i ing – e iew & edi ing, Valida ion, Supe ision, Resou ces, P ojec
adminis a ion, Me hodology, In es iga ion, Funding acquisi ion,
Concep ualiza ion.
E hics s a emen
The au ho s decla e ha all p ocedu es we e pe o med in compli-
ance wi h ele an laws and ins i u ional guidelines and ha e been
app o ed by he E hics Commi ee o Resea ch in Li e and Heal h Sci-
ences (CEICVS) om he Uni e si y o Minho.
The s udy adhe ed o he ene s o he Decla a ion o Helsinki and
was app o ed by he E hics Commi ee o Resea ch in Li e and Heal h
Sciences o he Uni e si y o Minho (SECVS 029/2014 (ADENDA), July
2, 2019). All subjec s signed an in o med consen wi h an explana ion o
he p ocedu es. This explana ion consis ed o a b ie desc ip ion o he
echnical p ocedu es o he exams.
Funding
This esea ch was unded by he Po uguese Founda ion o Science
and Technology (FCT) in he amewo k o he S a egic Funding UIDB/
04650/2020. The au ho J.G. is also suppo ed by he PhD g an
2020.08737. BD om FCT.
Decla a ion o compe ing in e es
None decla ed.
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