Maths, Physics Revision Physicss Maths Physics Physics A Level Physics Home Maths Maths Revision hut g.c.s.e. OPTICS Fig.1 Fig 2 Long sightedness hyperopia Concave lens F Convex lens F A convex lens is a converging lens. This time the  parallel rays on the outside converge to the focal  point F The retina is the light sensitive part at the back of the eye Short sightedness Myopia Fig 3 A short sighted person can see near objects but not distant objects Light rays from a distant object  focus in front of  the retina. (Fig 3) A concave lens helps to rectify this problem by diverging the rays So that the eye lens can focus the rays on the retina. (Fig 4) Fig 4 Eye Ray diagrams