Select the appropriate option and complete the following paragraph.
(cornea, faint, conical, rod, image, coloured, retina, colours, myopic, presbyopic, colour blind) The ____ in our eyes consists of many light sensitive cells. These cells are shaped like a rod and like a cone. The ____ shaped cells give information about the intensity of light to the brain. The ____ cells give information about the colour of the object to the brain. Brain processes all the information received and we see the actual image of the object. Rod shaped cells respond to ___ light also but conical cells do not. Thus we perceive ____ only in bright light. Some people cannot recognize few colours or cannot distinguish between different colours. These persons are said to be _____. Apart from not being able to distinguish between different colours, their eye sight is normal.

Explanation

The retina in -our eyes consists of many light sensitive cells. These cells are shaped like a rod and like a cone. The rod shaped cells give information about the intensity of light to the brain. The conical cells give information about the colour of the object to the brain. Brain processes all the information received and we see the actual image of the object. Rod shaped cells respond to faint light also but conical cells do not. Thus we perceive colours only in bright light. Some people cannot recognize few colours or cannot distinguish between different colours. These persons are said to be colour blind. Apart from not being able to distinguish between different colours, their eye sight is normal.