![]() Measurement of straylight under large angle and small pupil conditions can be used for quantitative assessment of eye wall translucency. In normal eyes, straylight values measured with photopic pupils are by approximation also valid for mesopic and scotopic pupils, such as in night driving. Pupil diameters decreased to photopic values under typical night-driving glare conditions. For large scatter angles and small pupil diameters, eye wall translucency contributes significantly to straylight in a wavelength- and pigmentation-dependent manner. ![]() To estimate the order of magnitude of pupil contraction in the typical glare situation, pupil reflexes resulting from the sudden appearance of headlight-equivalent bright lights were recorded in three subjects in a laboratory environment.įor natural pupils (between 2 and 7 mm diameter), straylight weakly depends on pupil diameter (within 0.2 log units). Data were analyzed to assess effects of (1) inhomogeneity of light-scattering over the pupil plane, (2) translucency of the eye wall, and (3) effects of the periphery of the lens. In the study of red-free light, a yellow-LED based system was used with the same five subjects for scattering angles of 3.5 degrees, 10 degrees, and 28 degrees. Straylight was measured as a function of pupil diameter ranging from 1.3 to >8 mm in five normal subjects by using a white-light, CRT-based system for scattering angles of 3.5 degrees, 7 degrees, and 14 degrees. Pupils should also have identical shapes. Pupils with oval shape are a sign of hypertension. Abnormal pupils can occur because of a damaged cerebral. Generally, normal pupil size in adults ranges from 2 to 4 millimeters in diameter in bright light and 4 to 8 millimeters in the dark. Also, pupil size changes with age children and young adults tend to have large pupils, and seniors usually have small pupils. The pupil must have a perfectly round shape. Some people have large pupils, and some people have small pupils. The assessment will also observe the shape of the pupil. In this study, the effects of pupil diameter and, especially in the case of small pupils, of eye wall translucency on the amount of retinal straylight were investigated. The pupil size is 2 to 5 mm and both should have the same shape. The typical disability glare is known to result from retinal straylight. Glare problems originating from bright lights are generally experienced more strongly at night. The limits of agreement between the Colvard pupillometer and the Nidek auto-refractor were assessed ().The limits of agreement are defined as the mean differences in between the two techniques ± 2S.D.The mean differences between the Colvard pupillometer and the Nidek auto-refractor are shown in Table 1.The mean difference was small (0.
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