We measure your quality of vision at 20 feet-this is the numerator (top twenty). The denominator (bottom 400) is a comparison to someone with standard vision. So if you have 20/400 vision you would have to be at 20 feet to see what one with standard vision would see at 400 feet.

20/400 does not correlate to your exact prescription, it is merely a measure of your vision without (hopefully) your eyeglasses or contact lenses on.

By Dr. Cook, O.D.

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Gray Family Vision Center

Gray Office

  Call Us: (207) 657-4488

  Fax: (207) 657-4574

  Hours:

Temporary Hours March 24th – May 19th, 2025
Monday: 8am – 5pm
Tuesday: 8am – 5pm
Wednesday: 8am – 6pm
Thursday: 8am – 7pm
Friday: 8am – 5pm
Saturday, Sunday: Closed

  Visit Us: 6 Turnpike Acres Rd., Gray, ME 04039

Windham Office

  Call Us: (207) 894-2174

  Fax: (207) 894-2236

  Hours:

Temporarily Closed

  Visit Us: 8 Crimson Drive, Unit 2, Windham, ME 04062

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