Correcting Vision Defects: Myopia and Hyperopia

Myopia (Short-Sightedness)

• Definition: A condition where a person can see near objects clearly, but struggles to focus on distant objects.
• Cause: Myopia occurs when light rays do not focus correctly on the retina. This can happen due to:
  • The eyeball being elongated, increasing the distance between the lens and the retina.
  • The lens being too thick or curved, causing light to focus in front of the retina.
• Correction: Myopia is corrected using a concave lens. This lens refracts (bends) the light rays before they enter the eye, allowing them to focus properly on the retina.

Hyperopia (Long-Sightedness)

• Definition: A condition where a person can see distant objects clearly, but struggles to focus on near objects.
• Cause: Hyperopia occurs when light focuses behind the retina instead of directly on it. This can be caused by:
  • The eyeball being too short, reducing the distance between the lens and the retina.
  • A loss of elasticity in the lens, preventing it from becoming thick enough to focus on near objects (often age-related).
• Correction: Hyperopia is corrected using a convex lens. This lens refracts the light rays, allowing the image to focus correctly on the retina.