This is caused by the cornea distorting vision because of its irregular curvature. So the lens of the eye is unable to bring all light rays into correct focus on the retina.
The lens is surrounded by these hard-working muscles that are used alter its shape.
In nearsightedness, the eyeball is too longs and the light rays focus in front of the retina necessitating concave lens. Also called this.
7 million receptor cells in the retina that are used for color vision.
This eye disease is caused due to high pressure built up by too much fluid.
Region of retina with dense concentration of cone cells, for enabling precise vision.
Called the white or white of the eye, it is the opaque (usually white, though in certain animals, such as horses and lizards, it can be black), fibrous, protective, outer layer of the eye containing collagen and elastic fibers.
Also known as visual purple, it is a pigment of the retina that is responsible for both the formation of the photoreceptor cells and the first events in the perception of light.
Ring of muscle that changes the size of pupil to regulate the amount of light entering the eye.
A little envelope of fluid the size of a vitamin pill, it is a transparent disk of tissue that changes shape for near or far vision. Used for fine-focusing the light rays.
Thin layer of light sensitive rod and cone cells that acts as a wallpaper where light is focussed on by the lens.
It is the connecting nerve from the eye to the brain.
The common name for the condition called 'Strabismus' in which the eyes are not properly aligned with each other.
This disease, common in older people, is characterized by the normally transparent lens becoming cloudy due to the change in protein fibers.
A type of refractive laser eye surgery performed by ophthalmologists for correcting myopia, hyperopia, and astigmatism. Many patients choose it as an alternative to wearing corrective eyeglasses or contact lenses. The procedure is generally preferred to photorefractive keratectomy, PRK, (also called ASA, Advanced Surface Ablation) because it requires less time for the patient's recovery, and the patient feels less pain.
Dime-sized transparent window at the front, it starts the seeing process by bending light rays into orderly patterns.
These glands secrete tears to keep the eye moist.
In farsightedness, light rays converge behind the retina causing a blurred image. Can be corrected with a convex lens and is also called this.
130 million receptor cells in the retina that are used for black-and-white vision.
Hole in the iris that becomes wider in dim light, it is the adjustable gateway for light.