Refractive errors and visual acuity assessment

Question 1

What is ametropia?

Answer 1

one or more of the optical parameters are less than perfect

into:

axial
and
refractive

leading to myopia or hypermetropia

Question 2

What is astigmatism?

Answer 2

where an eye is not completely symmetrical and hence light rays are not evenly bent

Question 3

What is presbyopia? How can it be corrected?

Answer 3

Long-sightedness in old age.

The inability to focus on near objects without glasses (loss of accommodation).

This can be corrected by positive lenses.