Vision and Ophthalmology Optics and Refraction

Question 1

A patient who is myopic has a far point located:

Accepted Answer

In front of the eye at a finite distance

Answer

A myopic eye is too long or too powerful, focusing parallel rays in front of the retina; the far point is at a finite distance in front of the eye.

Question 2

Which type of lens is used to correct myopia?

Accepted Answer

Concave (minus) lens

Answer

Concave (diverging, minus) lenses diverge light rays before they enter the eye, effectively moving the focal point back onto the retina in myopic patients.

Question 3

Presbyopia results from decreased ability of the lens to:

Accepted Answer

Accommodate (change shape) for near vision

Answer

Presbyopia occurs due to age-related loss of lens elasticity and ciliary muscle effectiveness, reducing the amplitude of accommodation needed for near focus.

Question 4

In a spherocylindrical lens, the power is equal in all meridians in which component?

Accepted Answer

Sphere only

Answer

The spherical component of a lens has equal power in all meridians, while the cylindrical component adds power in only one meridian to correct astigmatism.

Question 5

What does the term 'axis' refer to in a cylindrical lens prescription?

Accepted Answer

Direction of no power (plano meridian)

Answer

The axis in a cylinder prescription specifies the meridian of no cylindrical power (the plano meridian), perpendicular to which the full cylinder power acts.

Vision and Ophthalmology Practice Test

Vision and Ophthalmology Practice Test

Vision and Ophthalmology Optics and Refraction