low vision

Question 1

disorders of the lens: what is refraction?

Answer 1

Refraction refers to deflection or bending of light as it it passes from one transparent medium to another in different density

Question 2

Disorders of Refraction

Answer 2

Hyperopia or “farsightedness”
Distant objects may be seen more clearly than objects that are near (near objects are blurry)
Anterior-posterior dimension of the eyeball is too short
Point of focus: behind the retina

Myopia or “nearsightedness”
Close objects appear clearly, but far ones don’t
Anterior-posterior dimension of the eyeball is too long
Point of focus: in front of the retina

Question 3

disorders of the lens: accommodation

Answer 3

Accommodation refers to the ability of the eye to adjust its focus from far to near objects by changing the shape of its lens.

Question 4

disorders of accommodation

Answer 4

Cycloplegia

Presbyopia

Question 5

what is paralysis of the ciliary muscles of the eye resulting in pupillary dilation

Answer 5

Cycloplegia

Question 6

Presbyopia

Answer 6

With aging, lens thickens and its capsule becomes less elastic
Inability to read small print or discriminate close objects
Worsening of symptoms:
Dim light
Upon arising in morning
Fatigue

Question 7

disorders of the retina: macular degeneration

Answer 7

characterized by degeneration in the central portion of the retina= resulting in loss of central vision

Question 8

is leading cause of reduced vision in elderly

Answer 8

Age-related macular degeneration (AMD)

Question 9

Affects 80-90% of individuals with AMD
Cause: Unknown
Progress more slowly than the wet type
Small white or yellowish deposits (drusen) form on theretina, beneath the macula, causing it to deteriorate or degenerate over time

Answer 9

Dry Macular Degeneration

Question 10

Affects 10-15% of individuals with AMD
Accounts for approximately 90% of all cases of severe vision loss from the disease
Abnormal blood vessels under the retina begin to grow toward the macula
Blood vessels break, bleed, and leak fluid
Result: Damage to the macula, causing it to lift up and pull away from its base
Rapid and severe loss of central vision

Answer 10

Wet Macular Degeneration

Question 11

disorders of the retina: AMD prevalence

Answer 11

>1.75 million individuals in U.S.
Age
Women
Caucasians
Cause: Unknown

Question 12

risk factors of AMD

Answer 12

Risk factors:
Cigarette smoking
Obesity
Low dietary intake (lutein, omega 3 fatty acids, zinc, Vitamins A, C, and E)
Genetics 
Race

Question 13

Disorders Intraocular Pressure: glaucoma

Answer 13

Chronic, progressive disease of optic nerve
A pressure-induced degenerative neuropathy that produces changes in the optic nerve and causes visual field loss.

Etiology:
Cause: Unknown
Risk factors:
Genetic
Age
Race
Hypertension

Question 14

leading cause of blindness in black ppl

Answer 14

glaucoma

Question 15

symptoms of glaucoma

Answer 15

Decreased or blurred vision
Headache
Sudden eye pain

Progression, if untreated:
Initially asymptomatic
Slow loss of peripheral vision
Loss of central vision

Question 16

types of glaucoma

Answer 16

extreme, advanced, early glaucoma

Question 17

A health care provider who specializes in refractive errors, prescribes eyeglasses or contact lenses and diagnoses and manages conditions of the eye as regulated by state laws.
May also perform low vision examinations

Answer 17

optometrist

Question 18

A physician who specializes in the medical and surgical care of the eyes and is qualified to prescribe ocular medications and to perform surgery on the eyes.

Answer 18

opthalmologist