Can you test your own eyesight? While most docs say you should see your eye doctor at least once every 2 years—even if you have 20/20 vision—many of us don’t. In fact, Census data says Americans are making fewer doctor’s appointments—just 3.9 visits a year per person, down from 4.8 visits a year per person 10 years ago. And while a routine eye exam doesn’t just test your vision, but your eye health, too (sometimes the first indicator of diseases like diabetes), these three DIY eye tests from Glenda Secor, OD, a fellow of the American Academy of Optometry, could give you insight into your sight. If you don’t like the results you’re seeing—or not seeing—book an appointment A.S.A.P. Check the time. See more clearly with your glasses than with your contacts? You might have astigmatism, or blurred vision caused by the shape of your cornea. Sometimes contacts under-correct astigmatism (non-astigmatism lenses are easier to fit and less expensive for patients). The good news is there are plenty of contacts on the market for those who have it. If you don’t wear glasses or contacts, focus on the hands and lines of an analog clock. If any lines appear blurrier than the others, it could signal astigmatism. When you have it, your eye corrects with an oval shape instead of a round shape, so some areas appear more clearly than others. See the doctor for a sure answer. Dark Adaptation. Ryan Gosling in Gangster Squad isn’t the only reason to head to the movies this week. Checking your eyes’ dark adaptation is a good way to test your eyesight. When you enter the dark theater, you should see everything clearly within a matter of seconds—same goes for when you leave the theater during the daytime. If it takes more than a minute for your eyes to adjust, you might have poor dark adaptation ability, a potential signal for larger issues like vitamin A deficiency. Computer Strain. If working at a computer all day leaves your eyes feeling heavy, sore, or very dry, your tired peepers are probably just that. But if you notice you have red eyes, are seeing spots, or are extremely sensitive to light, you could have an eye infection that only a routine eye exam can detect. If the problem is plain old tired eyes, wake them up by taking 60-second breaks every hour to look away from your screen. Elevate your chair and lower your monitor to a few inches below eye level—when you look down on something, you’re more likely to blink and produce tears, so your eyes aren’t as dry. More from Prevention: 5 Steps To Age-Proof Your Vision