Crystalline Lens, Presbyopia and Cataracts Flashcards
The anterior-most layers of the crystalline lens are called:
a. Nucleus
b. Cortex
c. Subcapsular epithlium
d. None of the above
None of the above
Cataracts will only form in the nucleus of lens.
a. True
b. False
False
The amplitude of accommodation for the average 50 year old is approximately:
a. 1.00 diopter
b. 2.50 diopters
c. 4.00 diopters
d. 6.00 diopters
1.00 diopter
The lens and capsule is surrounded by a fluid called vitreous humor that nourishes the capsule and lens:
a. True
b. False
False
As a patient ages, the lens becomes larger and more flexible.
a. True
b. False
False
Ophthalmologists always wait for a cataract to ripen before extraction.
a. True
b. False
False
The type of cataract extraction that causes the least insult or injury to the eyes is called:
a. Phakoemulsification
b. Otracapsular
c. Extracapsular
d. Couching
Phakoemulsification
Prolonged periods of near vision use may lead to near point stress, and the development of:
a. Myopia
b. Hyperopia
c. Astigmatism
d. Cataracts
Myopia
Sitting upright and reading or working at a longer distance may help prevent near point stress.
a. True
b. False
True
When the cilliary muscle contracts it moves closer to the lens equator, relaxing the zonules (suspensory ligaments) and increasing the plus power of the lens.
a. True
b. False
False
A hyperopic patient with presbyopia can remove his/her glasses to see clearly at near.
a. True
b. False
False
Swelling of the area of the retina that is responsible for the central vision following cataract surgery is called:
a. Corneal edema
b. Papilledema
c. Cystoid macular edema
d. None of the above
Cystoid macular edema
A secondary cataract forms:
a. In the cortex
b. In the nucleus
c. In the subcapsular epithelium
d. In the posterior capsule
In the posterior capsule
Cataract surgery can now be performed using a laser to remove the lens.
a. True
b. False
False
Presbyopia is caused by loss of:
a. Elasticity of the capsule
b. Cilliary muscle tone
c. Elasticity of the lens
d. All of the above
All of the above
A congenital cataract is the result of:
a. Traumatic injury
b. Smoking
c. Birth
d. Exposure to ultraviolet light
Birth
At birth, a child will have approximately _____ diopters of accommodation:
a. 4-6
b. 8-10
c. 12-14
d. 16-18
16-18
Monovision is a fitting/surgical technique used to allow one eye to see near, while the other sees in the distance. It is preferable to fit the dominant eye with the near Rx.
a. True
b. False
False
The lens is composed primarily of water and protein.
a. True
b. False
True
The fibers that comprise the lens are about 10nm long and _____ in shape.
a. Cresent
b. Square
c. Oval
d. Hexagonal
Crecent
