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Free-space accommodative response and minus lens-induced accommodative response in pre-school children

Chen AH, O'Leary DJ

Optometry, 2000 Jul;71(7):454-8.
PMID: 15326899

The purpose of this study was to investigate and compare the accommodative accuracy of pre-school children between free-space accommodative stimulus and minus lens-induced accommodative stimulus.

Matched MeSH terms: Accommodation, Ocular/physiology*
Is there any difference in using blur as a stimulus for accommodation between emmetropes and myopes?

Chen AH

Documenta ophthalmologica. Advances in ophthalmology, 2002 Jul;105(1):33-9.
PMID: 12152800

The purpose of this study was to determine if there was any difference between myopes and emmetropes in using blur as a stimulus for accommodation when the chromatic aberration, size and proximal cues were eliminated. Twenty adults (10 myopes and 10 emmetropes) were examined for their accuracy of accommodation response for five different accommodation demands (OD, 1D, 2D, 3D, 4D) under two different light sources: achromatized white light versus monochromatic light. There was no significant difference in using blur stimulus between myopes and emmetropes when the chromatic aberration, size and proximal cues were eliminated.

Matched MeSH terms: Accommodation, Ocular/physiology*
Virtual reality games on accommodation and convergence

Mohamed Elias Z, Batumalai UM, Azmi ANH

Appl Ergon, 2019 Nov;81:102879.
PMID: 31422241 DOI: 10.1016/j.apergo.2019.102879

Increasing popularity of virtual reality (VR) gaming is causing increased concern, as prolonged use induces visual adaptation effects which disturbs normal vision. Effects of VR gaming on accommodation and convergence of young adults by measuring accommodative response and phoria before and after experiencing virtual reality were measured. An increase in accommodative response and a decrease in convergence was observed after immersion in VR games. It was found that visual symptoms were apparent among the subjects post VR exposure.

Matched MeSH terms: Accommodation, Ocular/physiology*
The Cambridge Anti-myopia Study: variables associated with myopia progression

Price H, Allen PM, Radhakrishnan H, Calver R, Rae S, Theagarayan B, et al.

Optom Vis Sci, 2013 Nov;90(11):1274-83.
PMID: 24100478 DOI: 10.1097/OPX.0000000000000067

To identify variables associated with myopia progression and to identify any interaction between accommodative function, myopia progression, age, and treatment effect in the Cambridge Anti-Myopia Study.

Matched MeSH terms: Accommodation, Ocular/physiology
Effects of long-term visual display terminal usage on visual functions

Yeow PT, Taylor SP

Optom Vis Sci, 1991 Dec;68(12):930-41.
PMID: 1787950

Since their rapid introduction into the workplace visual display terminals (VDT's) have been the source of a number of studies aimed at detecting effects on office workers. The published studies have been either short-term or cross-sectional, with one exception. The results have shown varying degrees of relation but by not having a comparable control group all have been limited in their value. We set out to monitor at regular intervals over a 2-year period specific visual functions that have been reported to be affected by VDT usage, and to compare VDT and non-VDT users in the same office environment. By assessing the VDT operators from the time the systems were introduced we have an accurate baseline to work from when assessing change due to the introduction of the VDT.

Matched MeSH terms: Accommodation, Ocular/physiology*
Fulltext Amplitude of Accommodation among Students of a Malaysian Private University as Assessed Using Subjective and Objective Techniques

Majumder C, Afnan H

Korean J Ophthalmol, 2020 06;34(3):219-226.
PMID: 32495530 DOI: 10.3341/kjo.2019.0138

PURPOSE: The purpose of the study was to establish baseline data for amplitude of accommodation (AA) measured using both subjective and objective techniques in students at a private Malaysian university.
METHODS: This cross-sectional study was conducted including 34 healthy participants with a mean age of 22.26 ± 1.88 years. AA was measured using dynamic retinoscopy and the push-up, pull-away, modified push-up, and minus-lens techniques.
RESULTS: The mean AA scores for the push-up, pull-away, minus-lens, and modified push-up techniques and dynamic retinoscopy were 11.38 ± 2.03, 10.35 ± 1.64, 9.24 ± 1.18, 8.26 ± 1.44, and 7.2 ± 1.0 diopters, respectively. No AA measurements showed significant difference among ethnicities (Chinese, Malay, and Indian). This study suggested that AA obtained using push-up (p = 0.005) and pull-away (p = 0.017) methods and dynamic retinoscopy (p = 0.041) were significantly different according to sex. No significant difference was observed in AA for the minus-lens (p = 0.051) and modified push-up (p = 0.216) techniques by sex. A moderately negative correlation was found between AA and age for the push-up (r = -0.434, p = 0.010), pull-away (r = -0.412, p = 0.016), and minus-lens (r = -0.509, p = 0.002) techniques and dynamic retinoscopy (r = -0.497, p = 0.003). A weak negative correlation was found between age and AA measured using a modified push-up technique (r = -0.393, p = 0.022).
CONCLUSIONS: Mean AA was highest for the push-up technique, followed by the pull-away technique, the minus-lens technique, the modified push up technique, and dynamic retinoscopy. The push-up and pull-away methods and dynamic retinoscopy showed a significant difference in measurement of AA between sexes.

Matched MeSH terms: Accommodation, Ocular/physiology*
The influence of age, refractive error, visual demand and lighting conditions on accommodative ability in Malay children and adults

Chen AH, Ahmad A, Kearney S, Strang N

Graefes Arch Clin Exp Ophthalmol, 2019 Sep;257(9):1997-2004.
PMID: 31273509 DOI: 10.1007/s00417-019-04405-z

PURPOSE: Near work, accommodative inaccuracy and ambient lighting conditions have all been implicated in the development of myopia. However, differences in accommodative responses with age and refractive error under different visual conditions remain unclear. This study explores differences in accommodative ability and refractive error with exposure to differing ambient illumination and visual demands in Malay schoolchildren and adults.
METHODS: Sixty young adults (21-25 years) and 60 schoolchildren (8-12 years) were recruited. Accommodative lag and accommodative fluctuations at far (6 m) and near (25 cm) were measured using the Grand Seiko WAM-5500 open-field autorefractor. The effects of mesopic room illumination on accommodation were also investigated.
RESULTS: Repeated-measures ANOVA indicated that accommodative lag at far and near differed significantly between schoolchildren and young adults [F(1.219, 35.354) = 11.857, p 0.05). Accommodative lag and fluctuations were greater under mesopic room conditions for all ages [all p

Matched MeSH terms: Accommodation, Ocular/physiology*
Fulltext Accommodation response to Chinese and Latin characters in Chinese-illiterate young adults

Radhakrishnan H, Hartwig A, Charman WN, Llorente L

Clin Exp Optom, 2015 Nov;98(6):527-34.
PMID: 26450168 DOI: 10.1111/cxo.12296

BACKGROUND: Differences in accommodation when reading Chinese, as compared to Latin, characters have been suggested to have a role in the higher prevalence of myopia in some Asian countries. Yeo and colleagues (Optom Vis Sci 2013; 90: 156-163) found that, in Chinese-literate children, accommodation was marginally more accurate (by less than 0.05 D), when reading Chinese text. This was attributed to the additional cognitive demand associated with interpreting the more complex Chinese symbols. The present study compared responses to single Chinese and Latin characters, while controlling for cognitive demand.
METHODS: The monocular accommodative response was measured in Chinese-illiterate adults (10 emmetropes, mean spherical equivalent: -0.07 ± 0.42 D, age: 29.9 ± 4.2 years; 11 myopes, mean spherical equivalent: -4.28 ± 2.84 D, age: 31.7 ± 4.6 years) with an open-field autorefractor. Four Chinese and three Latin characters (approximately 1.15 degrees subtense) were individually presented on a display screen one metre away from the subject, while their vergence was varied over the range zero to 5.00 D using spectacle trial lenses. The slope and the accommodative error index (AEI) were calculated from the accommodative stimulus/response curves (ASRC).
RESULTS: No statistically significant differences were found between refractive groups or among characters within the same refractive group in ARSC slopes (Latin: 0.87 ± 0.14 for myopes versus 0.81 ± 0.12 for emmetropes; Chinese: 0.84 ± 0.12 for myopes versus 0.85 ± 0.12 for emmetropes). No significant differences were found between characters in accommodative error index either (Latin, 0.78 ± 0.42 D for myopes versus 1.15 ± 0.72 D for emmetropes; Chinese, 0.74 ± 0.37 D for myopes versus 1.17 ± 0.83 D for emmetropes). However, accommodative error indices and accommodative errors were significantly higher for emmetropes.
CONCLUSION: Under controlled cognitive demand, Chinese and Latin characters elicited similar responses in both individual refractive groups. This study fails to support the hypothesis that development of myopia in some Asian populations is associated with larger lags of accommodation when reading or viewing Chinese characters.
Study site: Manchester, United Kingdom

Matched MeSH terms: Accommodation, Ocular/physiology*