the human eye

Cards (11)

the human eye is a light gathering instrument, what actually lets us 'see'? 
the brain using the retina
how does the retina work?
it contains cells that generate electrical impulses when light strikes them. the electrical impulses are then carried by the optic nerve to the brain
eye accommodation
what is eye accommodation?
when the muscles around the eye lens change the shape eye lens to allow us to focus
hyperopia .
what can cause hyperopia?
either the retina and lens are too close or the cornea and lens combination is too weak
how do you correct hyperopia?
a converging lens shape called a positive meniscus is used. this is because the lens is thicker in the middle and it looks better
what is presbyopia?
the loss of eye accommodation due to the eye lens losing elasticity as you age
what is myopia?
nearsightedness
what causes myopia?
the distance between the retina and the lens is too large or the cornea and lens combination is too strong
how do you correct myopia?
using a diverging lens shape called a negative meniscus because of the thinner middle and the cosmetics