The human eyeमानव नेत्र

NCERT Fig 10.1 · interactive diagram

Parts and their functions

• Cornea (कॉर्निया (स्वच्छ मंडल)) — Thin transparent bulge at the front. Light enters here and most of the refraction happens at its outer surface.
• Iris (परितारिका) — Dark muscular diaphragm that controls the size of the pupil.
• Pupil (पुतली) — Opening that regulates the light entering the eye. Small in bright light, large in dim light.
• Aqueous humour (नेत्रोद (जलीय द्रव)) — Clear liquid between the cornea and the eye lens.
• Eye lens (crystalline lens) (नेत्र लेंस (क्रिस्टलीय लेंस)) — Convex lens of fibrous jelly. It fine-tunes the focal length so the image falls on the retina.
• Ciliary muscles (पक्ष्माभी पेशियाँ) — Change the curvature of the eye lens. Relaxed → lens thin, long focal length (far vision). Contracted → lens thick (near vision).
• Vitreous humour (काचाभ द्रव) — Jelly filling the eyeball behind the lens.
• Retina (दृष्टिपटल (रेटिना)) — Light-sensitive screen. A real, inverted image forms here; its cells send signals to the brain.
• Eyeball (नेत्र गोलक) — Nearly spherical, about 2.3 cm in diameter.
• Optic nerve (दृक् तंत्रिका) — Carries the electrical signals from the retina to the brain, which interprets them as images.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 10.1. Report a mistake