Question

Why we can't see the book placed in a dark room

Answer 1

In order to see the human eye must have light, we se objects because light reflects off them and into the eye, past the aqueous humor then to the pupil Light reaches its final destination within the photo receptors of the retina: the retina is the inner lining of the back of the eye.. The focused light is projected onto its flat, smooth surface. Signals sent from the photo receptors travel along nerve fibers to a nerve bundle which exits the back of the eye, called the optic nerve. The optic nerve sends the visual signals to the visual center in the back of the brain where the experience of vision occurs. 


when there is little or no light this process is unable to occur, so vision is either unclear or just plain black, so of course the capability to focus on writing in a room insufficient of light is weakened and the writing is hard to read. 

Answer 2

For seeing any object , light should fall on it . When light falls on an object , it is reflected back to our eyes and thus we are able to see things but in a completely dark room , no light is present so we are not able to see the object i.e. book .

Hope it helps........