Test, eye chart: This test measures how well you see at various distances. The eye chart itself -- the usual one is called Snellen's chart -- is imprinted with block letters that line-by-line decrease in size, corresponding to the distance at which that line of letters is normally visible.

The letters on Snellen's chart are, not surprisingly, called Snellen's test type. Each block letter is quite scientific in design (so that at the appropriate distance the letter subtends a visual angle of 5 degrees and each component part subtends an angle of 1 minute).

The chart and the letters are named for a 19th-century Dutch ophthalmologist Hermann Snellen (1834-1908) who came up with them as a test of visual acuity. Visual acuity refers to the clarity or clearness of the vision, a measure of how well a person sees. The word "acuity" comes from the Latin "acuitas" = sharpness.

How to Order  |  Price List  |  Refill Orders
Home  |  About Us  |  Contact Us  |  FAQ

Buy cheap canadian prescriptions from a Canadian Internet Pharmacy leader. cheap online pharmacy canadian pharmacy prescription drugs online discount medicine pharmacies online mail order prescription medication canadian online pharmacy search for online drugs canada pharmacies discount canadian medication drugstore Plavix Fosamax Lipitor Celebrex Actonel Flomax Glucophage Premarin Prevacid Evista .