Wednesday, 29 May 2013

Seeing

Our ability to see upon our eyes ability to bend light and focus the light onto the retina. The light is bent by the cornea and the lens. Once the image comes into focus on the retina, the optic nerve transient an electrical message to the brain so that we can process the information. The iris changes size to alter the amount of light that enters the eye.If the image fails to be focused on the retina, the image will appear blurred.



Short sighted vision
Myopia is the medical term for nearsightedness. People with myopia see objects more clearly when they are close to the eye, while distant objects appear blurred or fuzzy. Reading and close-up work may be clear, but distance vision is blurry.


Long sighted Vision
Also known as hyperopia is an abnormal condition of the eye in which vision is better for distant 
objects than for near objects. It results from the eyeball being too short from front to back, causing images to be focused behind the retina. 


No comments:

Post a Comment