Blind spot in the eye is devoid of ability of vision. Why?

If aperson uses spectacles of Power +1.0 dioptre, what is the nearest distance of distinct vision for him ? Given that near point of the person is 75 cm from the eye.

Draw a labelled diagram of human eye and explain the terms :far point ,Power of accommodation , persistence of vision and the least distance of distinct vision for a human eye.

A telescope has an objective of focal length 50 cm and eye-piece of focal length 5 cm.the last distance of distinct vision is 25 cm.The telescope is focussed for ditinct vision on a scale 200 cm awya from teh objective.Caculate the sepration between the objective and eye-piece

A telescope has an objective of focal length 50 cm and eye-piece of focal length 5 cm.the last distance of distinct vision is 25 cm.The telescope is focussed for ditinct vision on a scale 200 cm awya from teh objective.Caculate the magnification produced.

For a normal eye, the far point is at infinity and the near point of distinct vision is about 25cm in front of the eye. The cornea of the provides a converging power of about 40 dioptres, and the leas converging power of the eye-lens behind the cornea is about 20 dioptres. From this rough data estimate the range of accommodation (i.e., the range of converging power of the eye-lens) of a normal eye.

Which property of the pigment is responsible for its ability to initiate the process of photosynthesis? Why is the rate of photosynthesis higher in the red and blue regions of the spectrum of light?

Does short-sightedness (myopia) or long-sightedness (hyper metropia) imply necessarily that the eye has partially lost its ability of accommodation? If not, what might cause these defects of vision?

What is Accomodation of eye? Write various defects of vision and their cause. How the eye of person suffering from nearsightedness and farsightedness may be corrected ?