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 Form 4 Biology: Response, reception and coordination questions and answers

Describe how accommodation in the human eye is brought about when focusing on a near object

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Answer Text:

- Light rays from near objects need to be bent
more for the object to focused on the fovea.
Divergent rays need more bending. A lens with more curvature on its surface bends light the most that is, thick and bulging lens, for this to happen the following event occurs:
Ciliary muscles contract this causes a decrease in the diameter of the ring of ciliary muscles.
Suspensory ligament attached to ciliary muscles become loose or slacken
This decreases the pull of suspensory ligaments on the lens and this results in the bulging outwards and becomes thicker.
Light rays are therefore refracted more in order to be focused sharply to form image on the retina.


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