18
May
What is normal vision? Come to think of it, what is vision? The majority of people consider it to be one of main senses, and in general they are almost right. But the more correct wording is that vision is a sensation or a sensory feeling. Doctors define vision as ability to percept color, light and disposition of objects in space as images. Humans and animals have optical vision though some other ways of perception also exist. Ultrasound sensation, characteristics of bats, is one of them. Like any organ in a body eyes can fulfil their functions wrongly or not…