|The quality and prescription accuracy of contact lenses filled through online vendors is improving with time. Photo: Getty Images.|
While companies like Warby Parker continue to try and expand their spectacle Rx footprint, a recent investigation found almost one in 10 prescriptions filled by three online vendors failed to meet national standards for optical quality, a result that was greatly improved over a 2011 investigation that reported roughly 45% of spectacles failed at least one optical parameter or impact testing.1,2
“Despite this improvement in spectacle prescription accuracy, other lens design elements impacting visual performance and ocular protection cannot be determined by the prescription alone,” the authors wrote in their paper.
Spectacle prescription numbers, such as sphere, cylinder and axis, don’t provide the additional information necessary to optimize the visual function and performance of the eyewear for an individual patient, they added.
Paid participants with no optical training and who were masked to the study’s objectives ordered spectacle lenses from the Internet. The prescription powers ordered (sphere, cylinder and axis) were statistically sampled from 1,000 previously filled prescriptions. A total of 100 orders were placed with three online vendors, and the orders included a range of high- and low-powered single vision lenses, progressive addition lenses and duplicate orders to assess repeatability. An independent certified testing lab was contracted to assess conformance with voluntary consensus standards and FDA drop-ball safety testing. Lenses not meeting these standards were counted as failures.
The overall failure rate for the three vendors was 11.2±3.2% (Vendor A), 8.0±2.7% (Vendor B) and 8.2±2.8% (Vendor C). The repeatability for 20 prescriptions ordered five times from each vendor was high, at over 90%.
Additionally, the researchers didn’t find any lens impact failures in the current study.
Despite these improved findings, there is a risk of decreased visual performance and potential harm to individuals ordering spectacles online, as they are likely to be unaware that their prescriptions do not meet national standards.1 When eyewear is ordered from an eye care professional, the finished lenses are assessed, and any lenses not meeting national standards are reordered, the investigators said.
“The consumer does not have the equipment or expertise to assess the accuracy or quality of ordered lenses. The potential risks are decreased visual effectiveness in the workplace, educational settings, recreational activities and driving, which may increase the risk of decreased vision performance, visual asthenopia, accidents or falls,” the authors wrote.
The lower failure rates in the present study may be caused from several factors, including the fact that lens fabricating technology is now widely available and quality control processes may have improved since the earlier study.1 Additionally, the 2011 study sampled a larger number of online vendors (10) with fewer orders per vendor (20) vs. the present study.
“It is our view that specific recommendations by an eye care professional who understands the unique visual tasks and lifestyle needs of a patient are required in most cases to produce an optimal eyewear design,” the researchers wrote.
1. Gordon A, Twa M, Cutter G, Kleinstein RN. Accuracy and repeatability of internet-ordered spectacle lenses. Optom Vis Sci. October 20, 2021. [Epub ahead of print].
2. Citek K, Torgersen DL, Endres JD, Rosenberg RR. Safety and compliance of prescription spectacles ordered by the public via the Internet. Optometry. 2011;82:549-55.