Formation of Image

• Light entering the eye is refracted successively at the cornea, the aqueous humour, the lens and the vitreous humour.
• The image is formed on the retina and the retina sends signal along the optical nerve to the brain, causing the sensation of sight.
• The image formed on the retina is inverted but is interpreted as erect.

Near Point and Far Point

• The average normal eye can focus objects easily from about 25 cm, i.e., the near point,to infinity, i.e. the far point.
• This range of distance of clear vision varies from one person to another and decreases with age.

Focusing an near object
Focusing an far away object

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