Cornea is the anterior portion of sclera which is external layer of eye. It is transparent and absorbs oxygen from the air and helps to focus light rays entering the eye.
Eye lens is a transparent and crystalline structure which is held in place by ligaments. It is biconvex and focusses the light rays on the retina.
Hence, both cornea and lens help in image formation on retina.
So, the correct answer is 'Transparent and help in image formation on retina'.