16 CFR Part 456 ; Agency Information Collection Activities: Review; Comment Request Ophthalmic Practice Rule (Eyeglass Rule): FTC Project No. R511996
Background: LensCrafters is a retailer of prescription eye wear and prescription sunglasses. It was founded in 1983 and has subsequently expanded to 948 stores in the U.S. , Canada, and Puerto Rico. The stores affiliate with either employed or independent optometrists who practice on-site or in an adjacent office. As part of the Federal Trade Commission's systematic review of all current FTC rules and guides, the FTC is seeking public comment on the efficacy, costs, benefits, and impact of the Ophthalmic Practices Rule (Eyeglass Rule). One of the questions to be answered is whether prescribers should be required to include a patient's interpupillary distance (PD) in a prescription for eyeglasses. ANSI Z80.1 defines the interpupillary distance for far vision as: The separation between the visual axes of the eyes in their primary position, as the subject fixates on an infinitely distant object, and the interpupillary distance for near vision as: The separation between the visual axes of the eyes, at the plane of the spectacle lenses, as the subject fixates on a near object at the intended working distance. Accuracy is critical: Accurate PDs are critical to ensuring that the optical center of the lens aligns with the center of the patient's pupil. Misalignment of these two points can cause prism, which results in visual discomfort. Accuracy in PD measurement is particularly important in higher prescriptions, since even a small misalignment can cause prismatically induced visual discomfort. Binocular PD alone is not sufficient for good alignment: More information is needed than just a horizontal PD, which is often taken binocularly. Vertical centration, pantoscopic tilt, and vertex distance in high prescriptions are all critical components to a well fit pair of eye wear. ANSI goes on to define the Monocular PD as The separation between the center of the bridge of the nose and the visual axis of the designated eye (i.e., right or left) for either distance or near fixation. The right and left interpupillary distances may not necessarily be equal. This means that a binocular PD is not always accurate. Due to normal facial asymmetry, monocular PDs are required for good centration. Many opticians now utilize a pupillometer or other digital technology to get an accurate monocular horizontal PD. Measurements are often taken with the frame on the patient's face to measure both monocular horizontal and vertical placement of the pupil within that fame's unique eye wire. Vertex distance and pantoscopic tilt are also taken into account. PDs are not routinely taken by prescribers as part of an eye exam: Optometrists and ophthalmologists do not routinely measure interpupillary distance as part of a comprehensive eye exam and are not required to do so in most jurisdictions. In addition, the digital technology required to accurately obtain these measurements does not typically exist in the doctor's space. Since PDs are required for lens manufacture, opticians are trained to take accurate measurements for proper frame alignment and are therefore the best people to do this. Conclusion: Requiring prescribers to begin including PDs with eyeglass prescription will result in manufacturing errors, greater lens misalignment and discomfort, and more dissatisfied consumers.