November 18, 2021

Does drinking coffee damage your eyesight?

A woman drinks from a coffee cup while wondering "Does drinking coffee damage eyesight?"

Drinking coffee increases your blood pressure, which can lead to complications with your eyesight. If you have a family history of glaucoma, you should be especially mindful of your caffeine intake, as there is a connection between glaucoma and coffee consumption in those with a higher genetic risk for the disease. Understanding the connection between coffee and eyesight can help you make informed decisions about your health.

Coffee and Glaucoma

A woman drinks from a coffee cup while wondering "Does drinking coffee damage eyesight?"

Coffee.” used with permission via Unsplash by Jason Yoder

Research led by the Icahn School of Medicine at Mount Sinai demonstrated a connection between daily caffeine consumption and the risk for glaucoma. However, this was only present in those with a high genetic predisposition for the disease. Among individuals with the highest genetic risk score for elevated eye pressure, the risk of glaucoma may increase more than three-fold in association with high caffeine consumption. However, the risk of glaucoma does not increase for those with a lower genetic risk score.

Caffeine intake is associated with an increase in intraocular eye pressure (IOP). Elevated IOP is a major risk factor for glaucoma. Therefore, excessive caffeine intake may increase the likelihood of developing glaucoma for some patients. There are many forms of glaucoma, but it is often caused by abnormally high pressure in the eye, which damages the optic nerve. Glaucoma has no warning signs. In many cases, individuals don’t realize that they have this condition until irreparable eye damage has already occurred. Glaucoma is among the leading causes of blindness for those over age 60.

Short-Term Effects of Caffeine

Caffeine increases blood pressure and blood sugar. There is also a link between coffee and eye pressure, with this sensation briefly following a high dose of caffeine for some people. Other short-term effects include:

  • Blurred vision
  • Eye spasms (myokymia)
  • Burning eyes
  • Tingling eyes

Though these symptoms are not hazardous to your overall health, they can certainly disrupt your day. If you’re drinking caffeine to help you wake up and focus, suffering from significant eye problems won’t help. Twitching, burning eyes and blurred vision after coffee can make it difficult to focus on the task at hand and may decrease your productivity far more than the caffeine initially helped. Some people ask, “Can coffee make you see spots?” While spots themselves shouldn’t appear, the other disruptive visual effects of caffeine can create a similar disruption and frustration.

Caffeine isn’t the only thing that can cause myokymia, though. If you’re suffering from twitching eyes, you may also want to consider your alcohol intake, sleep schedule, and stress levels. Allergies and dry eyes can cause twitching and irritation as well. Address the potential culprits one at a time to determine the cause of your eye spasms and relieve this discomfort.

Long-Term Effects of Caffeine

High blood pressure can have many negative effects on your eye health. These are most likely to occur with sustained high blood pressure. Drinking too much coffee one day may not lead to long-term eye damage, but drinking an excessive amount of caffeine every day is more likely to cause problems. High blood pressure can lead to:

  • Damaged retina
  • Bleeding in the eye
  • Blurred vision
  • Vision loss
  • Fluid buildup under the retina (choroidopathy)
  • Nerve damage in the eye (optic neuropathy)

Choroidopathy and optic neuropathy can lead to impaired vision or vision loss. It’s important to get medical help at the first sign of impaired vision so your doctor can properly diagnose the problem and take action as early as possible. Many types of vision loss are irreparable, so you should seek medical attention promptly when you notice something wrong with your eyes.

Positive Effects of Coffee

Though coffee has its dangers when consumed in high quantities, it also offers many health benefits when used in moderation. Some studies have shown that caffeine can increase tear production, which may help prevent dry eye. Dry eye, in turn, can cause itching and irritation, so it’s important to maintain proper lubrication.

Caffeine can offer additional health benefits, such as a decreased risk of:

  • Type 2 diabetes
  • Parkinson’s disease
  • Liver disease

In moderation, caffeine can help increase alertness, improve memory, and enhance your mental functioning. The key is to consume caffeine in small amounts and not large doses.

How Much Coffee is Too Much?

To maintain your health, it’s generally recommended that you drink less than four cups of coffee a day, which typically provides 400 milligrams of caffeine in total. A 2012 study at Harvard Medical School found an increased risk of exfoliation glaucoma associated with drinking three or more cups of coffee a day, or about 300 milligrams of caffeine.

It’s important to note that coffee is not the only source of caffeine. If you’re wondering whether or not energy drinks can cause eye problems, the answer is yes. You need to consider all of the caffeine that you’re ingesting.

In addition to coffee and coffee drinks like espresso, caffeine may be found in:

  • Tea: A cup of black tea has about 47 mg of caffeine, while green tea has 28 mg.
  • Soda: A 12-ounce can of soda typically contains between 30 and 70 mg of caffeine.
  • Chocolate: A single ounce of dark chocolate has about 24 mg of caffeine.
  • Energy drinks: A 16-ounce energy drink usually has about 170 mg of caffeine.
  • Supplements: A caffeine supplement delivers about 200 mg.
  • Medications: Some medications contain caffeine. Excedrin, for example, has 50 mg in each dose.
  • Chewing gum: Some manufacturers now offer caffeinated chewing gums that have 40 to 100 mg of caffeine.

Watching your caffeine intake is always a good idea. Try to consume no more than 400 mg a day from all sources to protect your eye health. If you notice that you’re consuming too much caffeine, step down your consumption gradually to avoid caffeine withdrawal, which may cause headaches, nausea, muscle pain, and irritability.

If you’re experiencing any trouble with your vision, it’s best to schedule an eye exam with Northeastern Eye Institute as soon as possible. It’s best to get an eye exam at least once a year to help identify any health conditions early. Routine preventive care is the best way to keep your eyes in good health.