Amblyopia

A decreased vision of one eye or amblyopia (also known as lazy eye) can have various causes and is not always an organic problem of the eye. The most common cause is strabismus or misaligned eyes. If a child suffers from strabismus, the information of the misaligned eye is suppressed by the brain, so that the young patient does not see diplopic images. The child then basically only sees with the healthy eye. Due to the suppression of the incoming visual stimuli from the misaligned eye, important cell structures are lost very quickly in the visual cortex.

Until the age of seven, the human visual system is still very plastic, and thus also very sensitive. This is why eye injuries, for example, represent a higher threat also for the healthy eye. Thus, covering minor eye injuries with a bandage for a long period of time should be avoided during early infancy. Amblyopia can already develop if the information flow from the covered eye to the visual cortex is suppressed for even only a few days.

In contrast to infants, adult strabismus, e.g. due to ocular palsy, does not lead to amblyopia.
The reason is that the adult’s visual system of the brain is already fully developed. Hence, the information of both eyes is sent to the brain and, unlike the young child, the adult patient suffering from strabismus sees diplopic images.