what is myopia and causes of myopia
Answers
Answer:
Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface.
There are mainly three types of human eye defects. and one of them is myopia.
MYOPIA - myopia is also known as nearsightedness. in this type of defect, the one who's suffering from this type of defect is able to see near by objects clearly but can't see far object clearly. here the image which must be formed on retina is formed in front of it.
CAUSES OF MYOPIA :-
- excessive curvature of the eye lens.
- elongation of the eye ball. means lengthening of the eyeball which causes the image to form in front of the retina.
SOLUTION - using a suitable power of concave lens.
other defects are :-
hypermyopia which is also known as farsightedness. here the person which this defect can see far objects clearly but can't see near by objects clearly.
presbyopia it happens because the power of accomodation of eye decreases with ageing. here the lens becomes less elastic i.e it makes difficult for aged people to focus on nearby close objects.