It’s not too far-fetched to say that regular eye examinations can save your vision – but would you believe that an eye test could save your life? In addition to our eyes being the windows to our souls, they are also little peepholes into our bodies (literally). Many life-threatening systemic diseases can first manifest as signs in our eyes, even before we begin to notice symptoms in other parts of the body. And to catch even more people unaware, some of these ocular signs occur without us realizing, making routine eye examinations a little more important than you previously thought. Here are some of the major conditions an eye test might detect.

Diabetes
Diabetes is a significant problem in the United States. The Centers for Disease Control and Prevention found over 1 in 10 Americans have some form of diabetes – however, roughly 20% of those with diabetes don’t realize they have it. Considering diabetes makes the top 10 causes of death list in the United States, any way of detecting the disease early is worthy of pursuing.

Your eyecare professional is able to pick up signs in the retina of your eyes that indicate diabetes while you’re still munching away on those fries, blissfully unaware that your blood sugar levels are skyrocketing. Your vision may yet be unaffected too, as you help yourself to seconds on that pasta. But with a thorough eye exam, what your eye doctor can see are little bleeds at the back of your eye as well as areas of depleted oxygen supply and leakage from damaged retinal blood vessels, all as a result of elevated blood sugars from diabetes. This early detection allows early intervention to lower those sugar levels before the nastier signs and symptoms of diabetes begin to show, such as kidney damage or reduced circulation to your extremities.

Hypertension
Although hypertension (high blood pressure) doesn’t explicitly make the top 10 list of leading causes of death in the US, it’s a major contributing factor in two of the conditions that do – heart disease and stroke.

Known as hypertensive retinopathy, signs in your eyes such as bleeding, fluid leakage, and subtle changes to the appearance of the blood vessels throughout your retina can alert your eye doctor to check your blood pressure or refer you to a physician who can investigate your risk of hypertension. Similar to diabetes, these signs may not translate to any disturbances to your vision and are only noticed on a routine eye exam. As hypertension often doesn’t present with any noticeable symptoms until you encounter one of its life-threatening effects like a heart attack, a diligent eye doctor could very well be the person to save your life.

Intracranial Hypertension
It’s not uncommon for patients to see an optometrist with the complaint of a headache. Headaches can be a result of myriad underlying conditions, including partying a little too hard the night before, but they can also signify an illness known as intracranial hypertension.

Intracranial hypertension refers to raised pressure around the brain, related to the cerebrospinal fluid that surrounds it, and can be either idiopathic (with no identifiable cause) or as a result of an underlying problem, such as a brain tumor or a blood clot in one of the blood vessels of the brain. In addition to headaches, symptoms of intracranial hypertension can include temporary blurring or “greying out” of the vision, neck stiffness, a ringing in the ears (tinnitus), and altered mental status. Idiopathic intracranial hypertension is not typically considered to be fatal though does carry a risk of permanent vision loss if not detected and treated in time. Conversely, intracranial hypertension from other causes such as brain tumor is a medical emergency. During an eye examination your eye doctor may notice a swollen optic nerve when checking the back of your eyes, a condition known as papilledema, as well as your pupils not reacting to light as they should – it can be a nasty surprise going to the eye doctor with a headache and expecting to walk out with new glasses but instead finding yourself in an ambulance on the way to hospital!

Eye cancer
There are several types of cancers that can affect the eye; not all of them are obvious but some can be life-threatening. Ocular melanoma is an aggressive form of cancer of the eye with the potential for metastasis, the spread of cancer cells to other areas of the body; an ocular melanoma metastasizing to the liver can be fatal. An early melanoma can easily go unnoticed as it develops painlessly inside the eye and cannot be seen by checking yourself out in the mirror. As the cancer grows larger and disrupts the surrounding tissues, symptoms may include blurred or distorted vision in the affected area of your retina, seeing flashing lights, or a distorted pupil. As treatment options and the likelihood of success depends on both the size and location of the tumor, catching the cancer early with a routine eye test can greatly improve your chances of saving both your eye and your life.

Cancers can also grow on the eyelids and visible areas of the eyeball, such as the whites of the eye. However, as our eyes and skin are often subject to various lumps and bumps, many of which are harmless, it can be difficult to pick which little spots you need to be worried about. An examination with your eye doctor under the slit lamp microscope can pick out features of a suspicious bump, such as its thickness, color, any crusting or ulceration, or changes to nearby eyelashes. In some cases, the examination will spot a bump you didn’t even realize you had. Basal cell carcinomas of the eyelid are slow-growing and do not metastasize; fortunately, these account for about 90% of eyelid cancers. The remaining 10% consist of more aggressive tumors, including squamous cell carcinoma, sebaceous cell carcinoma, and malignant melanomas, which can spread to other parts of the body, including the brain.

Attending for regular eye tests is a small price to pay for the chance to possibly catch a life-threatening condition and extend your life a number of extra years. Though you may feel your vision is a perfect 20/20, remember that an eye examination can reveal so much more (other than your vision actually not being as good as you thought it was). The American Optometric Association recommends adults undergo an eye test at least every two years. High-risk patients may choose to see an ophthalmologist (eye specialist) for their routine examinations.