It is not difficult for even person blessed with normal vision to appreciate the value of vision. In terms of clarity of vision, as well as in terms of variety of shapes and range of colours preceived, man fares better than most animals. The excellence of the sense of sight has tempted man to rely almost exclusively on it for pursuit of food and safety. this is in contrast to animals who depend a lot more on smell and hearing for these activities. Perhaps through disuse, man has suffered a blunting of other sense, particularly that of smell. It is difficult for a man with his eyes closed to find his way around, and to steer himself safely on the road for even a short distance. In addition,much of our knowledge about the world comes through our eyes. Apart from these necessities, vision is also the means by which we can enjoy and appreciate beauty, colour and brightness of the world.
–Adapted From “The Human Machine”- by R L Bijlani & S K Manchanda”
BIOLOGY 