Hx and Exam Flashcards
normal vision on snellen chart?
see letters with no6 at 6m
6/6 vision
what happens on a snellen chart if you cannot see the top letter
reduce the distance, count fingers, hand movement, light perception
what is WHO grade of blindness
3/60
how is visual acuity determined
snellen chart
determining colour blindness?
FM100
ishiharas test
testing of near vision?
measure sight by reading at the normal reading distance
occlude one eye then the other
describe the testing of the pupils?
observe pupils in bright room for anisocoria, then dim room
look for direct and indirect reflex then swinging light reflex for RAPD
how could you test lens accommodation
as object is brought closer to the pupils constrict slightly
how is the optic nerve assessed
colour
contour
cup
assessment of colour within optic nerve
disk has a yellow rim and nerve is paler yellow/white
assessment of contour of optic nerve
margin
assessment of cup of optic nerve
look at ratio of how much it makes up of the optic nerve
centre of optic disk
what may cause pale optic disk
ischaemia or demyelination
what may cause optic nerve demyelination
optic neuritis - maybe MS
B12 deficiency
ethambutol
what is emmetropia
no refractive error with light focused on retina
