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NSR:National Skill Registry

CATAGORIES
Anatomy of Eye
The Cornea
The Iris & Pupil
Aqueous Humour
Vitreous Humour
The Lens
The Retina
The Optic Nerve
Cillary Muscle
Sclera
Choroid

Eye Anatomy - The Retina

The eye’s retina is the inside back surface and is often compared to camera film – with good reason. It is densely filled with light-sensitive cells that receive images brought in by light rays. The cells are of two types:

  1. Six to seven million cones – which provide color perception and sharp vision in bright light;
  2. 75 to 150 million rods – which provide vision in dim light;

In the 1990s, a third type of retinal cell was discovered -- photosensitive ganglion cells. They detect the rising and setting of the sun and affect the body’s sleep-wake pattern. The first published writing about them was in 2000.

The retina (about 0.5 mm thick) is the innermost of three layers that make up the eyeball’s wall. The layer outside the retina is the choroid. It is filled with blood vessels that bring nutrients and oxygen to the retina and carry away its waste products. The outermost layer of the eyeball wall is the sclera, which we see in front as the “white” of the eye and the cornea. It is a tough, protective layer

 



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