ST. LOUIS—Consumers who order prescription eyeglasses online often receive glasses that fail to comply with optical tolerance and impact resistance requirements, according to a newly released study conducted by the American Optometric Association in conjunction with the Optical Laboratories Association and The Vision Council

The study, which was published in the September issue of Optometry: Journal of the American Optometric Association, found that nearly half of the prescription eyewear ordered online in the U.S.—44.8 percent—had incorrect prescriptions or did not meet physical parameters to provide sufficient protection to the wearer.

Over a two-month period in 2010, 10 individuals from across the U.S. ordered two pairs of glasses, including pairs for both adults and children, from each of 10 of the most visited online optical vendors, for a total of 200 pairs of glasses. Frame styles were chosen from the mid-range options offered by each vendor, in varying frame materials, lens styles and prescriptions. The AOA's published article did not identify the online optical vendors/retailers selected for the study.

Of the eyeglasses ordered, 154 pairs were received. After they were received, lens analysis included measurement of sphere power, cylinder power and axis, add power (if specified), separation of distance optical centers and center thickness.

Several pairs were provided incorrectly such as single vision instead of bifocals, or lens treatments that were added or omitted, the AOA reported. In 29 percent of glasses received, at least one lens was not within the parameters of the prescription. Nearly 23 percent of the lenses failed impact testing, based on center thickness and lens treatment. Of the children's glasses tested, 29 percent failed impact testing.

Karl Citek, OD, PhD, a lead study author from Pacific University College of Optometry, noted that patients who purchase eyewear without the assistance of a trained professional may not receive a product of equal performance, value or safety. “Patients do not receive the benefit of ensuring an accurate prescription and a proper fit,” he wrote.

Sam Pierce, OD, trustee for the AOA, said consumers should be cautious when ordering any medical devices online. "Although online retailers may effectively market cost savings associated with online purchase of eyewear, consumers should beware, as this study points out, that the lack of oversight and quality control can lead to inferior products that could be harmful," Pierce said.

Click here to download a PDF file of the study.