Optha Errors of Refraction Flashcards
0
Q
Uses principles of waves to describe the behaviour of light
A
Wavefront optics
1
Q
Uses line diagram to depict the behaviour of light
A
Geometric optics
2
Q
Vergence:
Diverging
Concave lens
A
Negative vergence
3
Q
Vergence:
Converging
Convex
A
Positive convergence
4
Q
Vergence in parallel or flat plane
A
Zero vergence
5
Q
Infinity
A
6 m or 20 ft or more
6
Q
Law of refraction
A
Snell’s law
7
Q
Diopters for cornea
A
40 D
Constant corneal refractive power
8
Q
Diopters for lens
A
20 D modifiable lens refractive power
9
Q
Focus exactly at fovea
No error of refraction
A
Emmetropia
10
Q
Present refractive error
A
Ametropia
11
Q
Near sighted
Image infront of retina
Long eyeball
Myopia
What lens?
A
Myopia
MY CAVE
12
Q
Far sight
Behind retina
Short eyeball
Hyperopia
Hypermetropia
What lens?
A
Convex
13
Q
+ diopters
A
Convergence
14
Q
- diopters
A
Divergence
