I have friends who have had serious permanent vision changes as a result of taking a reasonable dose of psychedelics one time (which is one of the main reasons I haven't tried it). If you overdose on either lsd or alcohol you'll have serious ill effects.
Vision changes are part of any intoxication, most avid alcohol users have them all the time. You have vision changes due to high blood pressure, so vision is perhaps not a KPI to put on the table as a major one.
