defective and correction Eye class 10th physics wala physics

Описание: Sure! Here's a clear explanation of defects of the eye and their correction methods:

🔍 Defects of the Eye and Their Correction

The human eye may develop vision defects when light is not properly focused on the retina. These are called refractive errors or defects of vision.

👁️ 1. Myopia (Nearsightedness)

Problem: Can see near objects clearly, but distant objects appear blurry.

Cause: Eyeball is too long, or cornea is too curved, so light focuses in front of the retina.

Correction: Use concave lenses (diverging lens) to spread out light rays before they enter the eye.

👁️ 2. Hypermetropia (Farsightedness)

Problem: Can see distant objects clearly, but near objects appear blurry.

Cause: Eyeball is too short, or lens is too flat, so light focuses behind the retina.

Correction: Use convex lenses (converging lens) to bend light rays more sharply so they focus on the retina.

👁️ 3. Astigmatism

Problem: Blurred or distorted vision at all distances.

Cause: Irregular shape of the cornea or lens, causing uneven focusing of light.

Correction: Use cylindrical lenses or toric lenses to correct uneven curvature.

👁️ 4. Presbyopia

Problem: Difficulty seeing near objects, especially with age.

Cause: Loss of elasticity of the eye lens due to aging.

Correction: Use bifocal or progressive lenses (combining convex lens for near and normal vision).

Other Correction Methods:

👓 Spectacles (Glasses)

🥽 Contact Lenses

👁️‍🗨️ LASIK/Laser Surgery (to reshape the cornea permanently)

👁 Intraocular Lens Implants (in special cases)

Let me know if you’d like diagrams or a simpler version for school-level notes!