Eye Disorders Flashcards
What causes myopia?
The eyeball is too long front to back making it hard for the lens to get thin enough
Image doesn’t hit the retinal layer
What is hypermyopia?
Unable to see close up
What causes hypermyopia?
The eyeball is too short front to back making it hard for the lens to get thick enough
Image exceeds retinal layer
Types of lenses
Concave
Convex
What does a concave lens do?
Scatters light
What does a convex lens do?
Focuses light
What’s an astigmatism?
An irregularity on the surface of the cornea
What is colour blindness?
Not producing the opsin for that come properly
Or can be a processing problem in the occipital lobe
Types of colourblindness
Dichromatic
Trichromatic
What is dichromatic colourblindness?
Two cones aren’t produced properly
What is trichromatic colourblindness?
Three cones aren’t produces properly
Black and white sight
What is glaucoma?
Build up of fluid in the eye Increased tension on the outside Increased pressure on the inside of the eye collapses blood vessels in retinal layer Retinal layer dies Causes blindness
What are cataracts?
Milky eye
Lens get irritated and secretes a protein to build up a protective layer
Makes the eye clouds
Cause by UV light
What is blindness
Loss of 90% or more of vision
Sooooo many causes
What is myopia?
Unable to see far away
Most common
