Human Eye and Colourful world — Chapter Summary

The eye ball is nearly spherical

The eye ball is nearly spherical. The cornea is a transparent protective membrane at the front. Behind it lies the aqueous humour, then the crystallin

A healthy adult sees objects comfortably

A healthy adult sees objects comfortably at about 25 cm. This value changes with age and person. It may be as close as 7 to 8 cm in young children and

The angle formed by rays from

The angle formed by rays from the extreme ends of an object at the eye is called the angle of vision. If it is below 60°, the whole object can be seen

Accommodation is the ability of

Accommodation is the ability of the eye lens to change its focal length. Ciliary muscles change the curvature of the lens. For distant objects, the mu

The eye lens forms a real

The eye lens forms a real and inverted image on the retina. The distance between the lens and retina is about 2.5 cm, so the eye must adjust its focal