A defeat of vision in which the points in one plane of an object appear is focus while those in another plane are out of focus is called.

 

 

A) Myopia B) Distortion C) Astigmatism D) Hypermetropia

Which of the following statements are true concerning the eye?

1. Farsightedness can be corrected with a diverging lens.

2. Astigmatism refers to a defect in which the surface of the cornea is not spherical. Instead, it is more sharply curved in one plane than another.

3. The far point of the normal eye is infinity.

4. The hyperopic eye focuses rays from an object at infinity in front of the retina; the myopic eye focuses rays from an object at infinity behind the retina.

A nearsighted person cannot see objects clearly beyond 15.9 cm (herfar point).
(a) If she has no astigmatism and contact lenses are prescribed forher, what power lens is required to correct her vision?

A nearsighted person cannot see objects clearly beyond 25 cm (her far point). If she has no astigmatism and contact lenses are prescribed for her, what a) power and b) type of lens are required to correct her vision?