Without a doubt, vision is one of the most important of your five senses. And caring for it is an essential part of your overall health. Vision tests are a vital component of routine eye care that preserves your eyes and this important sense. Ideally, an optometrist or ophthalmologist will perform a comprehensive eye exam every year to two years, depending on your age and specific needs. He or she will examine the structure of your eyes and test how well they work. The exam usually takes about an hour and consists of the following routine eye tests: • Cover tests determine how well your eyes work together. It allows the doctor to find any misalignments such as “lazy eye.” You’ll be asked to focus on a small spot across the room while the doctor alternates between covering the right and left eye. • Depth perception is tested in a variety of ways. Some ask you to identify a “raised” picture within a group of several objects.Another test involves wearing a pair of 3D glasses while looking at a picture of several items and then choosing the one that appears closer. • Dilation involves special eyedrops being used to widen your pupils. The doctor then uses a special light called a slit-light to examine your cornea, retina, and iris’. He or she will be looking for signs of corneal ulcers, macular degeneration, and cataracts. • Ocular motility testing looks at how well your eyes follow a moving target and how well they move between two fixed targets. Your doctor will ask you to keep your head still while following an object, usually his or her finger, with your eyes. You may also be asked to quickly move your eyes back and forth between two non-moving objects. • Refraction uses a specialized instrument called a phoropter to determine your exact prescription. While sitting in a chair you’ll look at an eye chart located about 20 feet away. The phoropter will be placed in front of your face, and the doctor will use it to test lenses of different strengths. You’ll tell him or her if the chart becomes easier or more difficult to read with each lense. The refraction test helps the doctor identify nearsightedness, farsightedness, and astigmatism. • Visual acuity tests measure the sharpness of your vision. Most people are familiar with this test because it uses the chart of letters posted to a wall called the Snellen chart. You’ll be asked to read the chart from about 20 feet away. Your final measurement is determined by the smallest row of letters you can accurately read. Routine eye exams performed by an optometrist or ophthalmologist are an important part of your overall health. They find and correct physical and visual problems that contribute to the quality of your eyesight. Understanding the individual types of vision tests performed during the exam helps you make informed health decisions.