A recent article in Australian Optometry contained anecdotal evidence of an optometrist whose patient had purchased progressive lenses online and couldn't use them. Further investigation found that the fitting height for these lenses was out by over 5mm. (The online business concerned will not be mentioned).
It was understood that no fitting height specification or specific PD was required for the purchase of these progressive lenses. These measurements are essential for the correct dispensing of multifocal and bifocal lenses, but are often not required for making purchases online.
Both multifocal and bifocal lenses have the potential to become a safety issue for both the wearer and the public if they are fitted incorrectly and the customer has inadequate information on their use.
These reasons though previously stated in lens information on this site, I thought so important that I write another short article to explain why Only Specs doesn't routinely dispense bifocals or progressive lenses. This also applied to high prescriptions in single vision as the same reasoning applies.
The only exceptions to this rule are refitting new lenses into your own frame that has previously had bifocal or progressive lenses and they are being refitted with the same type of lens. Or you purchase a frame and have the fitting heights and PD measured by a trained dispensor or optometrist.
Adapted from Australian Optometry Vol 29 No. 7