Question

Image in human eye is formed at :

• A. Iris
• B. pupil
• C. cornea
• D. retina

Hint:

Think of the eye like a camera:
The lens system (cornea + eye lens) focuses light.
The {retina} acts like the film or sensor in a camera, where the sharp image needs to be formed. The iris and pupil control the amount of light, similar to the aperture in a camera.

Answer 1

The Correct Option is D

Concept: The human eye functions like a camera, focusing light from external objects to form an image on a light-sensitive layer. Step 1: Understanding the parts of the human eye and their functions
Cornea: The transparent outer layer at the front of the eye that covers the iris, pupil, and anterior chamber. It refracts (bends) light and contributes significantly to the eye's total focusing power.
Iris: The colored part of the eye that surrounds the pupil. It controls the size of the pupil, thus regulating the amount of light entering the eye.
Pupil: The opening in the center of the iris that allows light to enter the eye and reach the lens and retina.
Eye Lens: A transparent, biconvex structure located behind the iris and pupil. Its function is to focus light onto the retina. The lens can change its shape (accommodation) to focus on objects at different distances.
Retina: The light-sensitive layer at the back of the eye. It contains photoreceptor cells (rods and cones) that detect light and convert it into electrical signals. These signals are then transmitted to the brain via the optic nerve, where they are interpreted as images. Step 2: Identifying where the image is formed The optical system of the eye (cornea and lens) focuses light rays from an object to form a real, inverted image. For clear vision, this image must be formed precisely on the retina. If the image is formed in front of or behind the retina, the vision will be blurred (as in myopia or hypermetropia, respectively). Step 3: Analyzing the options
(1) Iris: Controls light entry, not where the image is formed.
(2) Pupil: The opening for light, not where the image is formed.
(3) Cornea: The primary refracting surface, but the final focused image is not formed here.
(4) Retina: Correct. The retina is the light-sensitive screen at the back of the eye where the focused image is formed. Therefore, the image in the human eye is formed at the retina.