Eye and Vision Flashcards
1
Q
How is visual acuity measured?
A
Snellen chart. Stand 6m away. 6/24 indicates poor visual acuity. Numerator is the distance from the chart, denominator is the smallest line that can be read.
2
Q
What factors influence visual acuity?
A
Optical factors. Retinal factors (the state of the cones) Stimulus factors (lighting, contrast)
3
Q
Why is the fovea important for visual acuity?
A
Fovea is the point where visual acuity is greatest. Fovea is at the centre of the macula, where cones are densely packed and there are no rods.
