Doctors Reveal How They Can Detect Cancer And Diabetes Just By Looking Into Your Eyes

Believe it or not, doctors with the right training can actually spot signs of serious health problems just by looking into your eyes.

We usually think of conditions like cancer or diabetes as things that need lab tests or body scans to detect. But in some cases, early signs can show up right there in your eyes—sometimes before any other symptoms start.

A basic eye exam can sometimes uncover health issues like diabetes, high cholesterol, high blood pressure, and even heart disease. Things like unusual redness or bright spots in your eyes might be early indicators of something more serious going on in your body.

While speaking with the Daily Mail, Dr. Raj Dasgupta, who serves as chief medical officer at Sleepopolis, explained that "A lot of diseases that affect the whole body can leave clues in the eyes because the eyes have tiny blood vessels, nerves and tissues that are really sensitive to changes."

Dr. Jacqueline Bowen, who is the president-elect of the American Optometric Association, added that eye doctors are able to detect as many as 270 different health conditions, even when those problems don’t seem related to your eyes at all.

Doctors have urged people to have annual eye exams Getty Stock Image

Dr. Dasgupta strongly encourages everyone to get their eyes checked once a year. He said that these exams can actually “give us early warning signs” before conditions get worse or begin to damage your vision.

So how exactly do eye doctors spot serious illnesses like cancer or diabetes just by examining your eyes?

How can you spot cancer in your eyes?

Those small dark specks on your iris that look harmless? While they might just be from too much sun exposure, they could also be one of the earliest signs of eye cancer.

In fact, any unusual dark or bright spots on the eye, or swelling that forms around your eyelid, could be an early red flag for eye cancer—even before your vision starts to change noticeably.

Also, if you notice a subtle yellow color forming around the whites of your eyes, it could suggest there’s a problem with your liver. It’s one of those small things that might go unnoticed if you're not paying close attention.

One particular kind of eye cancer is called ocular melanoma. It can develop in the uvea, which is the middle layer of your eye. If you spot a dark patch inside the eye, it could be related to this type of cancer since the uvea produces melanin, the pigment that gives color to our skin and eyes.

Dr. Dasgupta points out that a dark spot is often the main symptom people notice. But flashes of light, blurry vision, or even changes in the size of your pupils can also be signs to watch out for.

Another form, retinoblastoma, usually affects the back of the eye and comes from genetic mutations. It tends to show up in scans as a white spot and is more commonly seen in children.

The good news is that this rare form of cancer has a pretty high survival rate—around 96 percent.

Doctors have also found that some cancers like breast or lung cancer can spread to the eye. These tend to show up as dark patches as well, so they shouldn’t be ignored.

Forms of cancer and diabetes can be found through an eye exam Getty Stock Image

How can diabetes be seen in your eyes?

Back in 2019, researchers discovered that 431,000 Americans had diabetes and didn’t even know it until they went for an eye checkup.

High blood sugar levels can end up damaging the tiny blood vessels in your eyes. On top of that, if you also have high blood pressure, it can make those vessels even more fragile, leading to a risk of them breaking and leaking.

This condition is called diabetic retinopathy, and according to the Centers for Disease Control and Prevention, it’s actually the leading cause of blindness in working-age adults in the U.S. before retirement age.

During an eye exam, a doctor can sometimes spot tiny blood vessels leaking into the white parts of your eyes. That alone might be enough to catch diabetes early before you start feeling any major symptoms.