clinical optometry

Question 1

Emmetropia

Answer 1

no refractive error; light focussed onto retina

Question 2

Ametropia

Answer 2

refractive error present; light focussed in front of or behind retina

Question 3

Anisometropia

Answer 3

significant difference between right and left ametropia

Question 4

Myopia

Answer 4

distance target blurred
light focuses in front of retina
negative lenses (concave)

Question 5

hypermetropia

Answer 5

near targets blurred
light focussed behind retina
positive lenses (convex)

Question 6

astigmatism

Answer 6

eye has unequal refractive powers at different meridia
causes distorted vision
cylindrical lenses

Question 7

presbyopia

Answer 7

the reduction in ability of the eye to accomodate fro close-work with age
requires a supplementry convex or positive lens in order to focus light from a near object onto the retina

Question 8

visual acuity

Answer 8

smallest letter on the chart that person can read, with best spectacle or contact lens correction

Question 9

pinhole acuity

Answer 9

smallest letter seen when viewing through a pinhole

this is an indication of the best visual acuity the person is likely to have once corrected