The effects of coffee on your eyesight

As great as it may taste, the most common reason for coffee consumption in the UK is to stave off tiredness. But did you know that some studies suggest there may be a link between coffee and eyesight? Let’s find out.

Retinal damage vs. coffee

The retina is located at the back of the eye. It receives and converts the light into electrical signals, which is then sent to the brain for you to see everything around you. Damage to this area is commonly caused by trauma but can also occur due to ageing.

Coffee contains antioxidants believed to help prevent or delay age-related retinal damage. A 2022 study published by Frontiers in Pharmacology found that the inflammatory response to macular degeneration (an age-related condition that affects central vision) could potentially be suppressed by caffeine, one of coffee's main constituents.

Dry eyes vs. coffee

Dry eyes is an eye condition that happens when the eyes no longer produce tears, or they dry too quickly. This deprives the eye of essential hydration and can result in swollen and irritated eyes. In most cases, dry eyes can be treated; however, it can permanently damage the vision if left untreated.

In 2004, the University of Wisconsin Medical School published a study that suggested caffeine increased the risk of dry eye. However, this theory was later debunked in 2012 by the University of Tokyo’s School of Medicine, which released a study stating that coffee may actually prevent dry eye by increasing tear production.

Could your symptoms possibly be a sign of dry eyes?

Glaucoma vs. coffee

Glaucoma is an eye condition that develops when fluid builds up in the front part of the eye, increasing pressure on the optic nerve. This eye condition is the leading global cause of irreversible blindness.

A 2021 study published in Ophthalmology suggests patients with a strong family history of glaucoma should cut down on caffeine intake. The study included more than 120,000 British participants and was conducted over three years. Researchers found that those who consumed more than three cups of coffee a day had a higher chance of developing glaucoma if they had a family history of this condition. However, there was no link between coffee and glaucoma for those who fell into the lowest genetic risk score group.

Eye floaters vs. coffee

Eye floaters are different shaped particles, such as dots, rings, and lines seen in your field of vision when you look at a bright background. Eye floaters are caused by a process called posterior vitreous detachment (PVD), where the clear jelly- like substance inside your eye changes. Eye floaters are usually age-related and mostly harmless.

There is currently no scientific evidence to suggest that coffee can directly increase eye floaters. On the other hand, consuming excessive amounts of alcohol can trigger the development of eye floaters. So, you may want to reconsider those booze-filled weekends every now and then.

Visual hallucinations vs. coffee

People who drink more than seven cups of instant coffee a day are considered three times more likely to experience visual hallucinations. This can affect your mental health by interfering with day-to-day functioning, such as experiencing hallucinations at work.

According to NHS experts, you should consume no more than 400mg of caffeine a day. This means you can safely enjoy around four cups of coffee daily. So, there’s no need to throw out the espresso beans after all! But do keep an eye on your daily caffeine intake – especially if you are experiencing hallucinations.

Eye pressure vs. coffee

Research shows that drinking caffeinated drinks such as coffee can cause your eye pressure to increase. Experts believe that when the pressure inside your eye gets too high, it can damage the optic nerve and might cause vision loss.

Drinking too much coffee can also lead to high blood pressure, causing retinal damage, bleeding in the eye, and blurred vision. High blood pressure can also cause:

• Fluid build-up under the eye (choroidopathy)
• Scarring of the eye
• Optic neuropathy (nerve damage)

Whilst very little research suggests that drinking coffee can directly affect your eyesight, there is no harm in moderating your caffeine intake and reducing if necessary.