Biology
Give the reason for the following:
(i) Medicines dropped in the eye flow down into the nose.
(ii) A person from bright sunlight outside enters a poorly lit room and feels blinded for a short while.
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Answer
(i) Nasolacrimal duct connects the eyes with the nasal cavity. Medicines dropped in the eye, sometimes flow down through this duct and come into the nose.
(ii) When a person enters a poorly lit room after being exposed to bright sunlight outside, they may feel blinded for a short while due to dark adaptation. The following changes take place in dark adaptation:
- Visual purple or rhodopsin, the pigment of rods, is regenerated which was earlier broken down due to bright light.
- Pupil are dilated permitting more light to enter the eyes.
These adjustments take a little time during which the person feels blinded.
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