Alcohol and your vision
The effect of alcohol on your eyes and vision depends on many factors, including how much, how often and even what you drink. It can have both short- and long-term visual effects, including blurry vision, double vision and dry eye. Even the occasional drink can affect your eyes in some ways.
Short-term effects of alcohol on the eyes and sight
When you drink alcohol, your vision may change in various ways during and shortly after drinking. For example, researchers found that people who have been drinking are likely to rate images as more attractive, widely known as the "beer goggles" effect.
Here are some other ways drinking alcohol may affect your eyes and your vision right away:
Bigger pupils and heavy drinking
Drinking large amounts of alcohol may temporarily but significantly increase the size of your pupils, though effects can vary from person to person.
Color vision impairment and drinking
Research has shown that color vision gets worse an hour to two hours after drinking alcohol. There may be long-term effects on color vision as well: One study found that young adults who drink alcohol, even occasionally, did worse on color vision tests than those who don't drink at all.
Double vision, blurry vision and drinking
Drinking alcohol can cause double vision (diplopia). While double vision from drinking is a temporary effect, this is just one of the reasons that drinking and driving can be so dangerous.
Blurred vision typically occurs at 0.10% blood alcohol level. The number of drinks it takes to get to that level varies based on sex, weight and other factors. For example, it may only take two drinks in an hour for a 100-pound woman to experience blurred vision or up to five drinks in an hour for a 240-pound man.
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Dry eyes and drinking
A large study investigating the effect of alcohol on dry eye disease found that women have a significantly higher risk of experiencing dry eye symptoms after alcohol use as compared with men. In fact, drinking alcohol did not cause any increase in dry eye symptoms for men.
Eye movements and drinking
One study found that having a 0.08% blood alcohol level (the legal limit for driving in most states) can affect various types of eye movements in healthy young adults. The presence of a specific type of nystagmus (rhythmic involuntary eye movements) can actually help police decide whether to arrest a driver for drinking and driving.
The horizontal gaze nystagmus (HGN) test is one of three main sobriety tests police use. In the HGN test, the officer will ask the driver to take off their glasses and follow an object with their eyes. The eyes of a person who is over the legal blood alcohol limit will be more likely to:
Bounce or jerk while following an object like a finger or flashlight
Jerk for more than a few seconds while looking all the way to one side
Show symptoms of nystagmus when looking to the side before the eyes reach 45 degrees (about the location of the shoulder)
The other two main sobriety tests police use are the Walk-and-Turn (WAT) test and the One-Leg-Stand (OLS) test. These tests involve walking in a straight line and standing on one leg.
Eye twitching and drinking
One or both of your eyes may twitch during or after drinking alcohol. While there are many causes of eye twitching, it may be wise to cut back on drinking for a while if you develop an eye twitch that may be alcohol-related.
Poor night vision and drinking
A Journal of Ophthalmology study found that night vision gets worse after drinking in both men and women. The more alcohol the subjects drank, the worse their vision became under low-light conditions. They saw halos and starbursts, had difficulty seeing contrast, and experienced longer recovery time after a bright light was shined in their eyes.
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