(a) A person cannot read a newspaper placed nearer than 50 cm from his eyes. Name the defect of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. Draw a ray diagram to show how this defect may be corrected using a lens of appropriate focal length. (b) We see advertisements for eye donation on television or in newspapers. Write the importance of such advertisements.

(a)

The defect of vision the person is suffering from is hypermetropia (or far-sightedness).

Ray Diagram illustrating Hypermetropia:

[A ray diagram should be drawn here. It should show parallel rays of light from a distant object entering the eye. Because of the shorter than normal eyeball or less converging power of the eye lens, the rays focus behind the retina. A dotted line should indicate where the rays would focus if the eye were normal.]

Two Possible Causes of Hypermetropia:

1. Short eyeball: The eyeball is shorter than normal, causing the image to focus behind the retina.
2. Weak eye lens: The eye lens has less converging power than normal, causing the image to focus behind the retina.

Ray Diagram showing Correction of Hypermetropia:

[A ray diagram should be drawn here. It should show a convex lens placed in front of the eye. Parallel rays from a distant object are refracted by the convex lens, converging them to focus on the retina.] The convex lens adds converging power to the eye lens, allowing the image to focus correctly on the retina.

(b)

The importance of advertisements for eye donation is significant. These advertisements aim to raise awareness about the critical need for corneal grafts and other eye tissues for transplantation. They highlight the following:

• Saving lives and restoring sight: Eye donation provides the gift of sight to individuals who have lost their vision due to corneal damage, glaucoma, or other eye conditions. A single eye donation can potentially restore sight to two individuals.
• Addressing the shortage of donor organs: There's a constant and significant shortage of suitable donor eyes. Public awareness campaigns are crucial for increasing the number of registered donors and decreasing waiting lists for eye transplants.
• Improving quality of life: Restoring sight through eye donation drastically improves the quality of life for recipients, enabling them to participate more fully in society and pursue their daily activities with independence.
• Ethical considerations and legal framework: The advertisements usually emphasize the ethical aspects of donation, ensuring transparency and compliance with legal procedures to respect the donor's wishes and maintain ethical practices.

In summary, eye donation advertisements play a vital role in educating the public, promoting a culture of altruism, and ultimately, helping save and improve the lives of people suffering from vision loss.