A person has a near point of 40 cm and a far point of 1.0 m. When looking through lenses of focal length 1.0 m, what is the nearest an object can be to be seen clearly?
a. 29 cm
b. 67 cm
c. 134 cm
d. 140 cm
e. 68 cm
[Ques. 2] A nearsighted person cannot see objects clearly beyond 70 cm (the far point). If the patient has no astigmatism and contact lenses are prescribed, what is the power of the lens required to correct the patient's vision?
a. 0.7 diopters
b. 1.4 diopters
c. 2.9 diopters
d. 7.0 diopters
e. 700 diopters
[Ques. 3] Glaucoma occurs because
a. the eye cannot accommodate properly.
b. the shape or size of the eye is not normal.
c. there is too much pressure in the fluid in the eyeball.
d. the lens is partially or totally opaque.
[Ques. 4] If a person is farsighted the corrective lens will
a. take an object at the near point and form an image at 25 cm.
b. take an object at 25 cm and form an image at the near point.
c. take an object at infinity and form an image at 25 cm.
d. take an object at infinity and form an image at the near point.
[Ques. 5] A farsighted person with astigmatism would be prescribed a lens that is
a. diverging only.
b. both converging and cylindrical.
c. diverging only.
d. both converging and cylindrical.
[Ques. 6] If a person has hyperopia that person
a. may have an unusually long eyeball.
b. cannot see near objects clearly.
c. cannot relax the ciliary muscle adequately.
d. cannot form images behind the retina.
[Ques. 7] In the normal eye the ciliary muscles that control the lens will relax
a. when viewing objects at the near point.
b. when viewing objects at infinity.
c. when viewing objects at a distance of 20 ft.
d. only when a person has his/her eyes closed.
[Ques. 8] The eye changes its f-number by
a. using the iris to change the size of the pupil.
b. using the ciliary muscle to change the focal length of the lens.
c. Both a & b are correct.
d. The eye does not change its f-number.
[Ques. 9] While a camera has film where the image is formed, the eye forms the image on the
a. pupil.
b. cornea.
c. retina.
d. optic nerve.
[Ques. 10] A given individual is unable to see objects clearly when they are beyond 100 cm. What focal length lens should be used to correct this problem?
a. 100 cm
b. 33.3 cm
c. 20 cm
d. 75 cm
e. 100 cm