CBSE Class 10 Answered

Light from our surroundings enters our eye through the dioptric media --- cornea, lens, aqueous humour and vitreous body. Among these, the anterior part of the cornea accounts for providing nearly 2/3 of the refractive power, because it has a highly curved surface and high refractive index.

Light stimulates the photoreceptors on our retina to produce nerve impulses, which will travel along the optic nerve to the visual cortex of our brain. The image formed on the retina is real, inverted and smaller. However, on interpretation by the brain, the images will be upright. This is an inborn ability. Some people put it in this way: we 'see' with our brain, not our eyes.