Biology Topic: The Human Eye – O Level Biology Tuition

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This was a question which was tested in one of the school’s exam papers:

Q) Explain why the detachment of the retina from the choroid would results in blindness.

Ans) The choroid is a system of blood vessels, located between the retina and sclera, which provides nourishment to the retina. When a portion of the retina becomes separated from the choroid this detached part loses its nourishment and results in a temporary decrease in vision. The vitreous is a clear gel in the eye which is attached to retina. Vitreous sometimes gets separated from retina which is mostly uneventful, but occasionally the retina is pulled with it causing retinal detachment. Sometimes fluid from the vitreous body passes through the retinal tear and detaches the retina from the choroid. As the retina is lifted away vision becomes darkened and distorted. If the detachment is small and in retinal periphery it may remain asymptomatic while involvement of macula may lead to total blindness.

Source: http://www.myeyeworld.com/files/detached_retina.htm