Rostock Glare Perimeter: a distinctive method for quantification of glare

Disability glare induced by headlights of oncoming cars has been associated with reduced quality of vision. This study aimed at developing the Rostock Glare Perimeter to quantify dysphotopsia effects under simulated realistic conditions.

Sixty phakic subjects of different ages were dazzled by a bright light source centered at a projection screen 3.30 m away from the subject's eye. Using a projected marker moving outward from the screen center with angular steps of 0.25° in 12 directions, the area where the subject cannot distinguish the white spot from the glare effects of the light source was determined. A corresponding mean radius in a field angle relative to the subject's eye was defined as a measure for disability glare. Monocular and binocular measurements were performed, and a separate repeatability and reproducibility study was executed to determine the precision of the Rostock Glare Perimeter.

A significant mean positive correlation of disability glare with age (r = 0.534, p < 0.001) was found. The disability glare ranged from 0.33° to 1.8°, and a strong (r = 0.93, p < 0.0002) binocular summation effect was found. The repeatability and reproducibility limit of the Rostock Glare Perimeter method is 0.14° for 95% confidence interval.

The Rostock Glare Perimeter method is sensitive to detect age-related disability glare differences and to find binocular summation for disability glare in a healthy population for small field angles with high angular resolution. These findings suggest that the Rostock Glare Perimeter method is a helpful device to quantify symptoms of glare.