HomeMAGNIFYING EYEGLASSES
Magnifying eyeglasses combine the patients refractive error (astigmatism, myopia, etc.) with the amount of magnification needed. The amount of magnification is dependent upon the amount of remaining vision and the size of the material to be seen.
When the two eyes are equal in vision, two lenses are utilized as long as it is under 3X magnification. Above 3X, only one eye can be used because of the close working distance required. How close the material must be held depends upon the amount of magnification. The following is the formula used to calculate the reading distance:
Multiply the amount of magnification by 4 to get the "Dioptric Power" of the lens. Divide the dioptric power into the number 40 to get the number of inches from the eye. IE: a 4X lens is 16 diopters. Divided into 40, we get a 2.5" working distance; a 5X lens is 20 diopters and has a reading distance of 2 inches.
In the LOW VISION EVALUATION we teach the patient how to hold the material at the proper distance for the lens prescribed.
Generally speaking, if a person can read with a magnifying glass, we can get them to read with magnifying eyeglasses.
Magnifying eyeglasses costs vary. With low level magnification, pricing the cost of single-vision lenses plus frame at any optical store will give good value. However, as magnification increases, the design of the lens must eliminate distortion resulting in a significantly higher cost- perhaps in the $500 to $600 range.
Pictured above are "doublet microscope" lenses costing between $800 and $1200.