16 CFR Part 456 ; Agency Information Collection Activities: Review; Comment Request Ophthalmic Practice Rule (Eyeglass Rule): FTC Project No. R511996
optometrists and ophthalmologists (like me) determine what prescription the patient needs to see well in their glasses. That prescription is then used by opticians for the lenses when they fit the frame that the patient chooses to their face. This is where the interpupilary distance comes in. Even though the interpupilary distance doesn't change, the measurement is important for fitting the frame to the patient's face. To have lens prescribers get the equipment and measure this adds time and cost that is unnecessary as opticians will likely repeat this.