The minimum distance of clear vision for normal human eye is ________ cm.

The correct answer is Option 2.

Key Points

• The minimum distance of clear vision for a normal human eye is 25 cm.
• This distance is also known as the near point of the eye.
• It is the closest distance at which the eye can focus an object clearly without straining.
• The ability to see objects clearly at this distance decreases with age due to presbyopia.

Additional Information

• Presbyopia
  • A condition associated with aging where the eye exhibits a progressively diminished ability to focus on near objects.
  • It is caused by the hardening of the lens inside the eye.
• Accommodation
  • The process by which the eye changes optical power to maintain a clear image or focus on an object as its distance varies.
  • It involves the adjustment of the lens shape by the ciliary muscles.
• Focal Length of the Eye
  • The distance between the lens and the retina, typically around 2.5 cm in a relaxed eye.
  • It is important for focusing light onto the retina to form clear images.
• Hyperopia
  • A condition in which distant objects can be seen more clearly than near objects.
  • Also known as farsightedness, it occurs when the light entering the eye is focused behind the retina.