The Human Eye – Structure, Working, and Vision Explained
The human eye is one of the most precious and sensitive sense organs that allows us to perceive the colourful world around us. Functioning much like a camera, it has a lens system that forms images on a light-sensitive screen called the retina.
Structure of the Human Eye
The human eye consists of several vital components:
Cornea: The transparent, curved outer membrane that allows light to enter the eye.
Iris: The coloured circular structure behind the cornea that controls the size of the pupil.
Pupil: The small, adjustable opening in the iris that regulates the amount of light entering the eye.
Eye Lens: A transparent, jelly-like lens that focuses light onto the retina.
Ciliary Muscles: Muscles that hold the lens and adjust its shape for focusing.
Retina: The light-sensitive layer at the back of the eye where images are formed.
Blind Spot: The point where the optic nerve exits the eye; no image is detected here.
Aqueous Humour: The clear fluid between the cornea and the lens.
Vitreous Humour: The jelly-like substance filling the space between the lens and retina.
Light entering the eye is refracted successively by the cornea, aqueous humour, lens, and vitreous humour before forming an image on the retina. The retina converts light into electrical signals, which are transmitted to the brain via the optic nerve for visual interpretation.
Working of the Human Eye
Light rays from an object enter through the pupil and are focused by the convex eye lens to form a real and inverted image on the retina.
The retinal cells convert light into electrical impulses, which the brain interprets to create a visual image, giving us the sensation of sight.
Function of Iris and Pupil
The iris adjusts the pupil size depending on light intensity:
In bright light, the pupil contracts to reduce light entry.
In dim light, the pupil enlarges to allow more light in.
This mechanism ensures comfortable and clear vision in varying lighting conditions.
Learnbymaps
Learnbymaps GK Mindmaps Economics – Visit Here
Learnbymaps GK Mindmap General Knowledge – Visit Here
Learnbymaps GK Mindmap Science – Visit Here
Learnbymaps GK Mindmap Geography – Visit Here
Learnbymaps GK Mindmap History – Visit Here
Learnbymaps GK Mindmap Polity – Visit Here
Learnbymaps GK Mindmap Math And Reasoning – Visit Here