>The study analyzed 200 pairs of glasses that had been ordered from 10 different websites. The lenses were analyzed based on a number of criteria, including measurement of sphere power, cylinder power and axis, add power (if specified), separation of distance of optical centers and center thickness. The AOA reports that in some cases, single vision lenses were delivered instead of the bifocals that had been ordered. In other cases, specific lens treatments were either added to an or were left off.
>>almost half of the eyeglasses tested in the study (the AOA reports the number at 44.8 percent) didn't have the correct prescription strength or presented problems with safety.
https://www.optometricsofchatsworth.com/blog/study-finds-saf...
>The study analyzed 200 pairs of glasses that had been ordered from 10 different websites. The lenses were analyzed based on a number of criteria, including measurement of sphere power, cylinder power and axis, add power (if specified), separation of distance of optical centers and center thickness. The AOA reports that in some cases, single vision lenses were delivered instead of the bifocals that had been ordered. In other cases, specific lens treatments were either added to an or were left off.
>>almost half of the eyeglasses tested in the study (the AOA reports the number at 44.8 percent) didn't have the correct prescription strength or presented problems with safety.