The Human Eye and Colourful World class 10th
- It gives a wider field of view.
- It enhances the ability to detect faint objects.
- It provides three dimensional view.
1 Differentiate between Hypermetropia and Myopia.
2. What is presbyopia ? Write two causes of this defect. Name the type of lens
which can be used to correct presbyopia.
3. The near point of a person suffering from hypermetropia is at 50 cm from
his eye. What is the nature and power of the lens needed to correct this
4. How is the amount of light entering the eye controlled ?
- (a) What happens to the size of pupil of our eye in (i) dim light, (ii) bright
light ? (b) Name the cells on the retina sensitive to (i) bright light, (ii) dim light.
2. (a) Draw a simple diagram of the human eye and label clearly the cornea,
iris, pupil, ciliary muscles, eye lens, retina and optic nerve. (b) Describe the working of the human eye with the help of the above
diagram. What is short sightedness ? State the two causes of short-sightedness. With the help of ray diagrams, show : (a) the eye defect short sightedness. (b) correction of short sightedness by using a lens.