― A good rule in life is everything in moderation and this advice certainly applies to alcohol. The World Health Organisation has set certain alcohol unit limits for men and women per week which allow for safe drinking. ∙ But how can drinking over these limits affect your sight? What damage or symptoms are you likely to notice? ∙ Alcohol, Eyesight And Driving ∙ Well, to start with, alcohol will probably affect the rate at which the iris in the eye narrows and enlarges, [...].