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प्रश्न
Give Reason:
When you enter into a dark room from bright because of sunlight, you can not see things for a few seconds.
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उत्तर
In bright light the visual purple or rhodopsin pigment is destroyed and the diameter of the pupil is reduced to allow the entry of less light.
संबंधित प्रश्न
A person suffering from the eye-defect myopia (short-sightedness) can see clearly only up to a distance of 2 metres. What is the nature and power of lens required to rectify this defect?
What is long-sightedness? State the two causes of long-sightedness (or hypermetropia). With the help of ray diagrams, show:
(i) the eye-defect long-sightedness.
(ii) correction of long-sightedness by using a lens.
A short-sighted person has a near point of 15 cm and a far point of 40 cm.
(a) Can he see clearly an object at a distance of:
(i) 5 cm?
(ii) 25 cm?
(iii) 50 cm?
(b) To see clearly an object at infinity, what kind of spectacle lenses does he need?
What is meant by optical illusion? Give one example.
You do not enjoy watching a movie from a very short distance from the screen in a cinema hall. Why?
Choose the odd one out from the following terms and name the category to which the others belong.
Endolymph, Tympanic membrane, Semi-circular canal, Blind spot
Name the common defects of the eye.
What are the causes of ‘Myopia’?
Assertion: Myopia is the defect of vision in which a person cannot see distant objects clearly.
Reason: This due to eye-ball being too short.
