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It is highly vascularised and deeply pigmented. In front of eye the choroid coat forms the iris
and lens. An opening called the pupil is present in the centre of the iris.
3. Retina Coats:
Retina is the sensitive part of an eye. It contains two types of receptor cell – the rods and
cones. Rods are sensitive to different shades of light but not to color. The fovea is yellow
spots of the retina are densely packed with cones. It is the part that is used when one
concentrates on something. E.g. when reading, seeing, etc. The lens is transparent, elastic
and biconvex in shape. It is attached by ligaments to the ring shaped ciliary muscles. The
aqueous humor is a clear, watery liquid between the cornea and the lens. The vitreous humor
helps in image formation and in maintaining the spherical shape of the eye.