Purchase this article with an account.
J.E. Gwiazda, F.A. Vera-Diaz, R. Held, F. Thorn; Accommodation after Image Blur Adaptation in Myopes and Emmetropes . Invest. Ophthalmol. Vis. Sci. 2003;44(13):4784.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Prolonged exposure to blurred images has been shown to produce perceptual adaptation (Webster et al, 2002). The purpose of this study was to test whether the reported change in perceived blur produced by exposure to blurred images was accompanied by a change in accommodation. Method: Young adult (18 to 31 yrs) myopic (n = 17) and emmetropic (n = 9) subjects participated in the study. Myopes were tested with contact lenses and had corrected monocular VAs of 20/20 or better. Accommodation was measured binocularly with the Power Refractor, an eccentric infrared photorefractor. Accommodation for a near target (high contrast text at 0.3 m) was measured every 0.04 seconds for 2 minutes before and immediately after 3 minutes of blur exposure, as well as during blur adaptation. Blur was induced using 80% density diffusing occluders in front of both eyes. In addition, accommodation was measured for a far target (high contrast letters at 4.0 m) before and after the near measurements, with each subject's initial far readings used as a baseline for calculating the accommodative responses at near. Results: Compared to the pre-adapatation level, myopes showed a significant (t = 3.03, p = 0.008) increase in the accommodative response at near after 3 minutes of blur adaptation, while accommodation to the near target in emmetropes did not change. Overall, the difference in accommodation at near from pre- to post-adaptation was significantly greater for myopes than for emmetropes (F = 6.05, p = 0.02). Conclusions: The refractive group differences in accommodative response may be related to differences in the habitual response to image clarity between myopes and emmetropes under normal viewing conditions. CR: None Support: NIH/NEI grant EY01191
This PDF is available to Subscribers Only