If your friends continue to drink after you have passed out or you remain sober long after they can no longer consume the alcohol you are taking, you shouldn’t have to blame yourself.
You shouldn’t blame your weight or muscle mass. Don’t blame your experience at the bar or a lack of it. The thing that you may just need to blame are your eyes.
According to a number of recent studies, eye colour is a pretty good indicator of alcohol tolerance. The same has also been ascribed with pain tolerance, risk for diabetes, and hand-eye coordination.
If you have blue eyes, Congratulations! Blue eyed drinkers, can hold their alcohol much better than their dark eyed peers. However, the reason for this is not completely known yet.
One possible culprit is melanin, the pigment that darkens brown eyes. A study conducted at Georgia State University found that more melanin would make people more susceptible to the effects of alcohol, increasing responsiveness to booze in terms of “perception, reaction time, motor skills, personality and physiological reaction.”
The researchers had a few suggestions for the cause behind this difference. On the one hand, melanin could speed up neural transmissions in brown-eyed people, increasing the speed of alcohol’s effects into the brain faster.
Alternatively, the endocrine system, which controls hormones responsible for all sorts of bodily functions, could respond differently to light waves that do or do not enter the eyes depending on eye colour. In either case, the less melanin in your system, the more drinks it takes to feel the effects of alcohol.
Meanwhile, researchers from the University of Vermont, who compared alcoholism rates among people with different eye colours, suggested genetic sequences determining eye colour and love of drink appear on the same chromosome.
Given that eye colour is not derived from one single gene but variations in 12 or 13 of them, it seems entirely possible there would be some genetic overlap between alcohol responsiveness and eye colour.
Whatever the reason may be, when it comes to how much you are able to hold your liquor, you definitely can count on your eyes.