An Overview of Your Eye Health By Troy Bedinghaus, OD | Reviewed by Richard N. Fogoros, MD Updated February 14, 2018 Print Your eyes are your windows to the world. Healthy eyes and vision make it possible for you to see and enjoy the world around you. When you think of what it takes to keep your body healthy, things like nutrition and exercise probably come to mind. But what does it take to have healthy vision? What does it mean to have healthy eyes?Take a look at the anatomy of the eye. What Makes Eyes HealthyHealthy eyes are eyes that see clearly and have no visible irritation or disease. But even though you think you are seeing your best and your eyes don't have any noticeable symptoms of disease, they may not be as healthy as they could be. The human brain is amazingly good at covering up slight vision problems. For example, your brain might compensate for a slight vision problem in your right eye by making you use your left eye more.This is the reason why having an eye exam is so important, especially for young children who may not even know the difference in having blurry or clear vision. Article Common Signs of Eye Cancer We Often Miss Article What Your Blind Spot Really Is When an eye doctor looks into your eyes, he or she can determine if you are seeing your best, and if your eyes are free of disease that could cause vision loss over time. During an eye exam, an eye doctor performs several simple tests to determine if the major parts of your eyes are working together correctly and efficiently enough to assure you are seeing your world with the best possible vision.What Influences Eye Health?Taking good care of your eyes will help keep them healthy and help to maintain good vision through the years. As you age, your eyes and vision will change. It is important to receive professional eye care, including dilated eye exams, to diagnose eye disease early enough to prevent vision loss. Taking care of your eyes also includes protecting your eyes from UV rays and eating healthy foods. A diet rich in lutein and omega-3s helps protect against eye disease.Of course, your family history will also determine your eye health in some ways. Having a family history of eye disease puts you at higher risk for developing the disease. Make sure your eye doctor is aware of your complete medical history.Why You Need an Eye ExamScheduling an annual eye exam is one of the most important steps you can take in protecting your eyes and vision. Vision is one of our most precious senses, yet vision and eye care is often neglected. The eyes provide hints about our overall health, as the dilated pupil can reveal the presence of undiagnosed problems throughout the body. An eye doctor can detect eye problems at their earliest stages, giving you time to be treated before major damage occurs to your eyesight. Regular eye exams also give your eye doctor a chance to help you correct or adapt to vision changes as you age. Article How Epiretinal Membrane Can Affect Your Vision Article Eye Movement Disorders of the Eyes What Happens at an Eye Exam?During a comprehensive eye exam, your eye doctor will perform several different tests and procedures to check your vision as well as the overall health of your eyes. A comprehensive eye examination takes about an hour and should consist of most of the following parts:Visual Acuity: A visual acuity test is a measure of how well you see. Your eye doctor will ask you to read letters on a chart while standing 20 feet away. The smallest letters you are able to read will be recorded as your visual acuity. The visual acuity test is a simple, but very powerful test. Although there are many other factors to consider, the closer a person's visual acuity is to normal or 20/20, the more likely that person's eye is healthy.Confrontation Visual Fields: A confrontation visual field is a quick check of your basic field of vision, including your central and side (peripheral) vision. Your eye doctor or technician will sit in front of you and ask you to cover one eye while you actively participate in the test. The results of a confrontation visual field can sometimes reveal problems in your neurological system. Extraocular Movements: This test measures the muscles that control your eye movements. It is usually a simple test conducted by moving a pen or small object in different directions of gaze. Restrictions, weaknesses, or poor tracking of visual objects may be uncovered.Pupillary Tests: Pupillary reactions (the way your pupils dilate and constrict in response to light) can reveal a lot about the overall health of your eyes and your body. Certain pupillary reactions can reveal neurological problems, including some serious conditions.Cover Test: The cover test measures how well your eyes work together. The cover test is a simple test in which the doctor asks you to fixate on a near or distant object. He covers one eye, pauses, and then uncovers it. He is evaluating your eye as it is uncovered, as it refixates on the target. The cover test is important for detecting eye muscle problems such as esotropia, an eye that crosses in, or exotropia, an eye that wonders outward.Retinoscopy: Retinoscopy is a test that gives your eye doctor a way to measure refraction. Usually performed early in an exam, retinoscopy provides your doctor a starting point to estimate your prescription for glasses, if needed. Retinoscopy is an objective test, which does not require much input from the patient. Article Learn about corneal haze and how it can affect your vision. Article Do Your Eyes Have Emmetropia? Refraction: Most people remember refraction as the part of an exam in which the doctor asks the patient, "Which lens is better, one or two?" Refraction is a subjective test to measure errors in refraction, such as nearsightedness, farsightedness, astigmatism, or presbyopia.Slit Lamp Examination: Eye doctors use an instrument called a slit lamp, also called a biomicroscope, to examine the front (anterior segment) and back (posterior segment) part of your eye. This is to evaluate the overall health of your eye.Tonometry: Tonometry is the measurement of your eye’s pressure, better known as IOP, or intraocular pressure. Your eye doctor will put a drop of anesthetic into your eye. He will then place a small amount of fluorescein (yellow dye). A small device called a tonometer is moved close to your eye so that it gently touches the cornea, measuring the pressure of your eye.Dilated Fundus Exam: The dilated fundus examination is usually the last step in a comprehensive eye examination. Your eye doctor will administer special eye drops to dilate your pupils. This increases the size of your pupil, giving your doctor a larger window in which to inspect your internal eye health. The doctor is able to examine the vitreous, optic nerve, blood vessels, macula, and retina. This is the test that usually comes with a gift: a pair of disposable sunglasses, which you may need as your eyes are likely to be sensitive to light for a bit. Note: You will not be able to drive for a short time after this test.Top 3 Reasons to Have an Eye ExamTo Test Your Visual Acuity: Your prescription needs to be checked on a regular basis to make sure your visual acuity is the best it can be. Annoying headaches or general fatigue are often caused by slight over or under-corrections of your prescription.To Check for Eye Disease: Many serious eye diseases often have no symptoms. Glaucoma is an eye disease that causes vision loss and is commonly known as the "sneak thief of sight." Conditions such as macular degeneration or cataracts develop so gradually that you may not even realize your vision has decreased. Diabetic retinopathy is a condition that may develop in diabetic patients. Early detection of these and other eye diseases is important for maintaining healthy vision.To Reveal Developmental Problems: Uncorrected vision problems in children often cause learning and reading difficulties, or contribute to other medical problems such as dyslexia and ADD. Uncorrected vision in children can often cause amblyopia (lazy eye) or strabismus (eye turn), which can cause permanent vision loss if not treated early in life.If Your Exam Uncovers an Eye ProblemIf your eye doctor discovers a problem with your eyes or vision, you will be informed immediately. In cases of small vision problems or simple eye infections, your eye doctor will most likely treat the problem the same day. If a larger problem is discovered, however, you will probably be re-appointed for further testing another day.A Word From VerywellBeing diagnosed with an eye disease can be very stressful and disturbing. Although it may be difficult, do all you can to understand more about the disease. Learning how to manage the disease and how to cope with vision loss that may occur can help relieve your fears.The amount of vision loss you suffer will vary depending on your diagnosis. No matter what diagnosis you receive, you can find ways to take charge of your vision and eye health. Never be afraid to ask for help from others and remember to stay positive. Know that challenges may arise, but you will be able to tackle them if you are prepared.Sources: Maintaining Your Vision. NIH Senior Health website.Normal Vision Development in Adults Under 40. American Academy of Ophthalmology website.Simple Tips for Healthy Eyes. National Eye Institute website.