Lens Effective Power Flashcards
1
Q
Define effective power of a lens
A
vergence that a lens produces at a position other than that occupied by a lens itself
2
Q
How to make a lens more positive
A
move the lens away from the eye
3
Q
How to make a lens less positive
A
move lens closer to the eye
4
Q
What is the vertex distance
A
Distance from the back of the lens to the cornea
