Question

If you shine a light into one eye both pupils will constrict. The best explanation for this is ________.

Select one:

a. a small portion of light always enters the other eye

b. This, in fact, does not occur; information from both eyes is always separated.

c. sensory input from the retinas of both eyes converges at the optic chiasm and information from each eye is delivered to both the left and right sides of the brain

d. information from one eye is directly and immediately transferred to the other eye to maintain alignment of the eyes

Answer 1

Option a is false as when a person examine a specific eye the other eye that is not examined will always be closed with a piece of paper and Also a little shade of light onto the other eye will not cause this constriction

Option b is false as as this will occur as a resul if the pathway crossing over and converge each other while propagation of the nerve impulses to the brain so it is false as both eye will constrict

Option c is correct as the sensory impulses that is taken by the retina with the help of photoreceptor will pass through afferent pathway and when they reach the optic chiasm they will converge. This will result in the specific pathway and reaching of signal to the both side of the brain . As the signal reach the both side of the brain it will lead to the constriction of the both pupil when light is shown

Option d is wrong as the information from one eye will not reach the other eye and this will not cause any change in alignment as it is the brain and the ocular muscle that determine the alignment of the eye and not the sensory impulses

:)