Clinical Optometry Flashcards
what is emmetropia?
when there is no refractive error
what is ametropia?
when there is a refractive error
what are the two types of ametropia?
hyperopia
myopia
what is another name for hyperopia?
long sightedness
what causes hyperopia?
light is not focussed on the retina - behind it
due to - smaller eye, weaker lens etc.
how is hyperopia managed?
converging lens
+, concave
what is another name for myopia?
short sightedness
what causes myopia?
light focussed before the retina
due to - larger eye, stronger lens etc.
how is myopia managed?
diverging lens
-. convex
what is anisometropia?
a significant difference between the right and left eye
what is astigmatism?
when the eye has unequal refractive powers at different parts causing distorted vision
how is astigmatism managed?
with cylindrical lenses
how is the retina shaped in astigmatism?
like a rugby ball
normal is like a football
what is presbyopia?
the reduction of the ability of the eye to accomodate for close work with age
how is presbyopia managed?
positive lens - reading glasses
