The Committee on Ophthalmic Procedures Assessment of the American Acad
emy of Ophthalmology suggested either contrast sensitivity or low-cont
rast visual acuity (VA) measured before and after adding a glare sourc
e as a test for assessing overall visual disability from immature cata
racts. We have developed a test that follows the Committee's three pri
nciples of design, and we report that the effect of glare on VA is con
siderably greater for recognizing low-contrast letters than for recogn
izing high-contrast letters. The effect of glare on VA increases progr
essively as letter contrast is reduced from 96% through 50%, 25%, 11%,
and 4%. The 25% chart (and possibly the 11% chart) gives the most sui
table sensitivity for eyes with immature cataracts. Neither age-relate
d brunescence and aging itself nor even the presence of a distinct opa
city necessarily produces high sensitivity to glare. The test is sensi
tive enough to detect an ageing effect even before the age of 45 to 55
years and to reveal large intersubject differences among normally sig
hted 19- to 25-year-old subjects.