VISUAL ACUITY Flashcards
1
Q
VISUAL ACUITY
A
the ability of the visual system to resolve fine detail + is a measure of the ‘minimum angle of resolution’
measure of smallest detail an eye can resolve once any refractive error has been corrected
2
Q
MINIMUM ANGLE OF RESOLUTION
A
smallest angle subtended at the nodal point of the eye by two points or lines when those they can just be resolved as being separate
3
Q
SNELLEN ACUITY
A
the snellen notation for visual acuity assumes that a standard observer has a resolution limit of 1 arc min (1’)
4
Q
STANDARD TESTING DISTANCE FOR SNELLEN ACUITY
A
6 metres in UK
aka normal visual acuity is 6/6
5
Q
VA OF 6/18
A
at a distance of 6m, a px can only resolve letters of a size that would be visible to a normal observer at a distance of 18m
