Through the eye of peopl

Boojho with perfect eyesight was finding it difficult to pass a thread through the eye of a needle. What can be the possible reason for this?

On seeing with unaided eye, the visual angle of moon at the eye is 0.6^(@) . The focal lengths of the objective and the eyepiece of a telescope are respectively 200 cm and 5 cm. What will the visual angle on seeing through the telescope?

Light from the sun is falling directly upon a Ramsden eye-piece consisting of lenses of focal length 0.05 m. Find the position of the image formed and trace the path of rays through the eye-piece.

Through which aperture light enters the eye ?

The defect in eye due to which the old people cannot see nearby objects clearly

The spectrum which we can see through our eyes is called.........