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< What does "20/20" mean in an eye test? In Canada, the standard placement of the eye chart is on a wall that's 20 feet away from your eyes. Since many eye doctors' offices don't have rooms that are 20 feet long, in a smaller room the eye chart may hang behind the patient chair, using mirrors to make it appear in front of you at a simulated distance of 20 feet. How a Snellen eye chart and a "tumbling E" chart might look at your eye doctor's office. The tumbling E chart tests the visual acuity of young children and others who can't read letters aloud. 20/20 vision is considered "normal" vision, meaning you can read at 20 feet a letter that most human beings should be able to read at 20 feet. Eye charts can be configured in various ways, but generally, if during an eye test you can read the big E at the top but none of the letters lower than that, your vision is considered 20/200. That means you can read at 20 feet a letter that people with "normal" vision can read at 200 feet. So at 20/200, your visual acuity is very poor. In Canada you are considered "legally blind" if your best-corrected visual acuity (meaning, your best distance vision with eyeglasses or contact lenses) is 20/200 or worse. To get a driver's license in most of the United States, your best-corrected visual acuity must be at least 20/40. Usually the 20/20 line of letters is fourth from the bottom, with 20/15, 20/10 and 20/5 below that. Not many people have 20/10 or better visual acuity, but many animals do, especially birds of prey, which have been estimated to have an acuity of 20/5 or even better.
What :February Event When:Feb.05.2020 Time: 5:30 'ish to 7:00 'ish
Join us for a couple of hours at this Boston/Italian themed eatery as we swap Geocaching stories and general camaraderie. Feel free to stop in and say hello or stay for a bite to eat ... , and don't forget to log the event as a find. turn in receipt to ' newcrew'