Question

explain structure of eye, briefly

Answer 1

our eye contains of eyelids, eyelashes,eyebrows and lachrymal glands. A thin layer , called conjunctiva covers the front portion of the eye. The eye ball is located in the  eye socket . only 1/6 portion of the eye ball is visible to us .
                  
             Eye has three main layers. they are sclerotic layer or sclera , choroid layer and retina. the outer most thick tough ,fibrous , non-elastic and white coloured layer is sclera . the sclera bulges and forms cornea . the end of sclera connects to the optic nerve . the second layer is choriod layer. this layer is black in colour and contains a lot if blood vessels. ait encloses the eye except the part pupill. the part formed by the choroid layer around the pupil is iris. Radial and circular uscles are present in the iris . biconvex lens is present immediately behind the pupil is attached to the ciliary muscles and suspensory lingaments .
                                 the lens dividesd the inner eye ball as aqueous chamber and vitreous chamber. aqueous chamber is filled with water like fluid whereas vitreous chamber is filled with jelly like fluid .
                           retina contains the cels , called rods and cones . the area of the vision , called blind spot  and the area of the best vision , called yellow spot  are present in the present in the retina. The yellow spot is called macula or fovea 

Answer 2

the outermost part of an eye is (1)cornea which act as a primary lens,and allows the light to enter.then O(2) aqueous humor which protect the eye from dust particles.(3)the eye lens which adjusts the focal length of the image on the retina,which is controlled by the cilliary muscles,which contract or relaxes to change its focal length (4) vitrous humor which stables the positions of cilliary muscles and lens (5)retina which act as a screen for the image formation the image formed is real and inverted (6) light sensitive cells(rods & cones) which recieves the image and send it through the optic the nerves in form of nerve impulse,and the brain interprets the image.