There’s one specific eye symptom, however, that you shouldn’t ignore. Read on to find out which potentially alarming change in your vision could be a sign of cancer. READ THIS NEXT: If You Notice This on Your Face, Get Checked for Cancer “A sudden change in vision, which does not clear with a blink or a moisture drop, should prompt one to seek medical attention,” says Howard R. Krauss, MD, surgical neuro-ophthalmologist and Clinical Professor of Ophthalmology and Neurosurgery at Saint John’s Cancer Institute at Providence Saint John’s Health Center in Santa Monica, CA.ae0fcc31ae342fd3a1346ebb1f342fcb There may be other sudden changes, such as new pain or discomfort. But specifically, blurry vision can indicate an eye melanoma, according to the Mayo Clinic, and even small melanomas “can cause some vision loss if they occur in critical parts of the eye.” Most of us have experienced blurry vision at one time or another, and there are various potential reasons for it. “There are many causes of sudden blurred vision—some worrisome, but some not,” says Krauss. In some cases, dry eyes are the culprit—especially since so many of us spend a good portion of our day staring at screens. According to the American Optometric Association (AOA), dryness in the eyes can feel “irritated, gritty, scratchy, or [burning].” Dry eyes may water, sting, and be prone to producing mucus, as well as interfering with vision. “Does the blur vary with a blink? If it does, in many cases it may be due to dryness of the eye and/or excess mucus in the eye,” Krauss explains. Using an over-the-counter moisturizing eye drop may reverse the blur if this is the case. READ THIS NEXT: If You Notice This With Your Eyes, Get Your Thyroid Checked, Doctors Say. Since some kinds of blurred vision can indicate cancer or another serious condition, Krauss suggests checking your symptoms. “Ask yourself, ‘What’s going on?’” he says, adding that you should look for accompanying symptoms such as lightheadedness, weakness, headache, and/or an altered sensation in another area of the body. “If you are safe, well, and not having other symptoms, analyze your vision,” Krauss advises. He suggests covering one eye at a time to assess whether the blurriness is in both eyes, just one eye, or only when both of your eyes are open. “Is there double vision or shadowed vision, and, if so, is it present in one eye, each eye or only when both eyes are open?” Krauss also recommends observing whether the blur occurs at all distances, involves other changes such as brightness, or involves “floaters, debris, bugs, squiggly lines, or veils.” These symptoms may mean you need to seek medical treatment. RELATED: For more up-to-date information, sign up for our daily newsletter. While it isn’t known exactly what causes eye cancer or how to definitively prevent it, you can practice eye-healthy habits that may reduce your risk of disease. The American Cancer Society notes the link between sun exposure and melanomas and suggests decreasing exposure and protecting yourself with clothing, sunscreen, and sunglasses. Other healthy habits include getting regular eye exams. “An eye exam helps detect eye problems at their earliest stage—when they’re most treatable,” says the Mayo Clinic. Your eye doctor can tell you how frequently to come in for wellness visits. Reducing your time in front of screens and practicing healthy contact lens habits—such as cleaning your contacts and taking them out regularly—are also ways to take care of your eyes. “Adding powerful vitamins, antioxidants, and minerals to your diet can improve your vision and overall eye health,” advises the AOA. Krauss advises that if you’re not sure about your blurry vision, you should contact an eye care professional. READ THIS NEXT: If You See Eye Floaters, It Could Be a Sign of This Chronic Condition.