Vision Disorders. 10/10 Flashcards
Cornea appearance
Transparent
what causes corneal ulcers
infection/injury/rubbing/lenses
what is a corneal ulcer
disorganised tissue
why must cornea be transparent
window to let light through
whats the cornea made of
collagen
what can scar cornea
abrasion
iris main function
regulate light entering the eye and stops glare
iris disorders can lead to
glare/difficulty seeing in dim light
when iris partially/completely missing from birth (name)
aniridia
most common lens disorder
cataract
why happens to lens with cataracts and what does it cause
lens becomes opaque
blur/glare
what leads to presbyopia
lens flexibility decreases with age
how many layers of retina are there
11 layers
what’s the biggest sign of retinal issue
patient reports distortion
common retinal disorders
macular degeneration, retinal detachment, retinoblastoma
what does curtained vision suggest
retinal detachment
cause of diabetic/hypertensive retinopathy, retinal vein/artery occlusion
disruption of blood supply to the retina
diabetic retinopathy symptom
initially none
bleeds can cause scotomas
hypertensive retinopathy symptoms
often none
blur
retinal vein/artery occlusion symptoms
sudden vision loss
what is glaucoma and why does it occur
group of disorders characterised by optic nerve damage due to high pressure in the brain
why does papilloedema happen
high pressure in the brain
symptom of papilloedema
blur, scotoma, headache
why does optic neuritis happen and whats the main symptom
inflammation (usually) due to demyelinating disease
sudden vision loss
how many eye muscles are there
6 on each side
3 main reasons eye muscles tend not to work properly
nerve problems
generalised muscle weakness
trauma
what is heterotropia
simple eye turns
what can happen if heterotopia is longlasting
may be no double vision
poor vision may develop in 1 eye through lack of use
why don’t children with heterutopia report double vision
brain switches off 1eye
what contributes to refractive error
eye size
corneal shape
lens shape
besides eye size what can effect focal point
corneal/lens shape
what happens if brain damage to primary visual cortex
scotoma
specific vision losses
what can happen if damage to high visual areas
cant focus on two objects at once
