State one function of iris in human eye.
State one function of iris in human eye.
The primary function of the iris is to control the size of the pupil, which in turn regulates and controls the amount of light entering the eye.
Marking Scheme
- 1Stating that the iris controls the size of the pupil / regulates the amount of light entering the eye. (1 mark)
Hint
Think about the dark muscular diaphragm behind the cornea that acts like an aperture of a camera.
Quick Oral Answer
The iris is a dark muscular diaphragm behind the cornea that controls the size of the pupil, thereby regulating the amount of light entering the eye.
Analysis & Explanation
According to the NCERT textbook, the iris is a dark muscular diaphragm located behind the cornea. Its main function is to adjust the size of the pupil. When the light is bright, the iris contracts the pupil to let less light in, and in dim light, it dilates the pupil to allow more light to enter, thereby protecting the retina and optimizing vision.
Common Mistakes
- 1Confusing the function of the iris with that of the ciliary muscles (which modify the curvature/focal length of the eye lens).
Interesting Facts
The texture and pattern of the human iris are highly complex and unique to each individual—even more unique than fingerprints. This is why iris recognition technology is widely used for high-security biometric identification.
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Frequently Asked Questions
How many marks does this question carry in CBSE Class 10 Science 2012?
This question carries 1 mark in the CBSE Class 10 Science 2012 examination.
Which chapter does this question come from in Science?
This question is from the chapter "The Human Eye and the Colourful World" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "The Human Eye" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2012 paper?
This is a Very Short Answer question from Section A in the CBSE Class 10 Science 2012 paper.