The effect of pterygia on contrast sensitivity and glare disability.

To detect subtle changes in visual acuity, we measured spatial contrast sensitivity in 12 patients with pterygium (Group 1) and compared their results with those from an age- and sex-matched control population (Group 2). Glare disability was also measured in each group. Measurements of contrast sensitivity were lower in Group 1 at all spatial frequencies than those of Group 2, independent of the testing device used. Glare disability was significantly increased in Group 1 compared to Group 2. Our studies indicate that contrast sensitivity and glare disability testing may provide additional objective methods for documenting impaired vision in patients with pterygium when Snellen visual acuity is minimally affected.