Alcohol, or any other drug which reduces the supply of oxygen in the bloodstream, can impair the sensitivity of the cones which, in

reduces the visual acuity of sharpness

Explanation:

When we drink alcohol in large quantities, it is common for the vision to be double and blurred and for the notion of distance and depth to be affected by a reduction in sharpness. The reason? The muscles that control the focus of vision are compromised by the effect of alcohol. This is because alcohol reduces the supply of oxygen in the bloodstream and can impair the sensitivity of the cones.

Some other symptoms can also be seen in the eyes after drinking alcohol. For example, redness. This occurs because of the reduction in the amount of oxygen in the red blood cells, responsible for the dilation of the blood vessels, which are in the white part of the eyes, the sclera. Another symptom that cannot be observed by outsiders, but can be felt by the drunk person, is the narrowing of the visual field. It is common for us to have the impression of a tunnel vision.