Lecture 3: Visual Deficits Flashcards
Concave lens= _______
Minus
Diopter ____-____ power
Light bending
Convex lens=___
Plus
Refraction is the way in which light
Bends as it travels from one transparent medium to another of a different density
Cornea(40 diopters)+lens(20 diopters)=____________
60 Diopters
Hyperopia is _____-sighted
Far
In hyperopia the lens ______ have enough light bending power
Does not
Myopia is _____-sighted
Near
In hyperopia the lens ______ light bending power or the eyeball is _______
Has too much
Too long
Astigmatism is when the cornea is
Not spherical
A ________ lens is used to correct am astigmatism
Spherical
Presbyopia is
The need for vision correction when you get older
With presbyopia, you can see _____ but _____ images are blurred
Distance
Close
With presbyopia there’s not enough _________
Accomodation
Normal age-related eye changes
Declining sensitivity, color perception, and contrast sensitivity.
Dryness-not enough tears
Decreases resistance to glare (tolerance 2.5x times greater at age 20 than 65)
Needing more time to adjust to different levels of light.
True or false: low vision is a normal part of aging?
False
Best possible correction for low vision is between ___ and ___
20/60
20/400
___________ is the leading cause of vision loss in Americans over 60
Macular degeneration (aka age-related maculopathy)
Macular degeneration is characterized by the gradual degeneration of the _____ cells
Cone
What are the two types of macular degeneration?
Wet or dry
Dry M.D is characterized by?
Atrophy of the retinal cells, seen as hypopigmentation of the retinal pigment epithelium
Wet M.D is characterized by
Exudate, scars, and rupture of blood vessels
Treatment is only for ____ M.D
Wet
The primary impact of M.D is on _____ vision
Central
M.D is characterized by
Areas of blurred vision, shadows, dark spots, or distortions
Diabetic retinopathy is the ______ cause of NEW vision loss in American adults between 20 and 74
leading
Almost 100% of people with type 1 diabetes and ___ of people with type 2 diabetes will develop some form of diabetic retinopathy
70%
What are the two types of diabetic retinopathy
Proliferative, non-proliferative
The more serious proliferative DR is associated with
New blood vessel growth, abnormal blood cells, etc.
True or false: macular edema can exist at any stage of DR
True
Damage to the optic nerve can be caused by increased pressure in the ______ segment, but no ______ is felt
Anterior
Pain
In glaucoma, _____ vision is affected, but often goes ______
Peripheral
Unnoticed
Treatment consists of medications (to slow aqeueous production)
Ok
__________ surgery is the most common surgery in the united states
Cataract
Cataracts are characterized by the proteins acumulated in the lens _______ together
Clumping
_______ is the leading cause of reversible blindness in developing countries
Cataracts
