The blur of ink on the page transforms into letters, words and sentences. The magic of spectacle lenses! If you have perfect vision, on the other hand, you must have experienced the opposite effect if you ever tried on someone else's glasses: orderly sentences transforming into a sea of swimming black letters.

The focusing mechanism of the eye was first explained by Ibn al Haytham (Haysam), a dedicated student of Imam al Hakim, the 17th Fatemi Imam. In his book, Optics, he illustrated how light reflected from an object, falls on the retina of the eye to create an image of that object. Much like the lens of a camera!

The retina of the eye is flexible to make necessary adjustments for distant and near vision. When the retina loses its elasticity lenses become necessary; convex or concave lenses have to be used to rectify the defect.

The discovery of lenses dates back to the middle ages. It is an Islamic invention, a gift of Islam to science, an invention that can be ascribed to our Imam. Several modern scientists like Kepler and Roger Bacon have acknowledged this fact and based their theories on this book on optics.