Original Articles
Temporary Miosis after Blinking Effect on Visual Function
2009 Volume 30 Issue 3 Pages 84-89
Details
2009 Volume 30 Issue 3 Pages 84-89
Purpose: We investigated the effect on visual function of temporary miosis after blinking.
Methods: Included in this study were 17 eyes from 17 normal subjects. We used a modifi ed CAT-2000TM (Menicon, Tokyo, Japan) with an electronic pupillometer built into the contrast visual acuity measuring device. Two types of blinking, spontaneous and voluntary, were used. We evaluated pupil size before (basic size) and after blinking (minimum size). Contrast visual acuity was measured after instillation of cyclopentolate hydrochloride (Cyplegin®) using an artifi cial pupil whose diameter was measured before and after blinking.
Results: Pupil diameters exhibited signifi cant temporary miosis after blinking. Pupil variation was about 0.5 mm with spontaneous blinking and about 0.5～1.5 mm with voluntary blinking. Contrast visual acuity increased signifi cantly, about 1 or 2 lines, when artifi cial pupil size reduced more than 1.0 mm from the basic size.
Conclusions: This study suggests that temporary miosis after blinking produces an increase in depth of focus and improves retinal image quality, there by affecting visual function.
