18. Accommodation, presbyopia. Flashcards
what is accommodation ?
focussing at different distances
process by which the eye changes ints optical power
how does the strength of the lens increase - short sighted?
by making it rounder - using the ciliary bodies
cillary muscle contract
becomes thinner - long sighted vision , strength of lens decrease
what is presbyopia ?
physiological loss in accommodation in advancing age
long sightendenss
figures close by appears blurry
why does presbyopia occur ?
deposition of insoluble protein in lens
elasticity of lens decreases
around what age does accomidation of lens become less than 3D ? and what are the reading abilities then and the symptoms
symptoms of presbyopia long sightedness ?
45 years of age - accommodation of the lens decreases by 3D
difficulty reading fine print , headache , visual fatigue
symptoms worst with dim light
what is the treatment of presbyopia?
reading glasses
bifocal lens - eliminate need for extra glass just for reading
implantation of accommodative intraocular lenses
laser blended vision
