I am going to cross post this message as it is extremely important for strabismics and for parents of strabismic children seeking prism lenses.
Be extra careful when ordering prism glasses as some opticians have no idea what to do with strabismic patients and may calculate their own pupillary distance (PD) measurement that will not be the same as the developmental optometrist's PD. The difference in the PD measurement can have disastrous effects on your prescription. Although Luxottica Retail says they'll change their training programs for their opticians after my incident, I don't know if they really will. Even if you go to non-Luxottica owned optical stores, make sure the optician doesn't override your doctor's prescription because of the "Standard Operating Procedure" for measuring PD.
I am not exaggerating when I say that what I experienced could have been fatal. Below is the description of what happened to me.
After two and a half LONG years in VT, I finally got a prescription for prism glasses in mid May. I went to Sears Optical to fill the prescription and after a long delay in making my lenses, I received a pair that almost caused me to crash my car because the pupillary distance was incorrectly calculated by the optician.
Effect: I had to drive with one eye closed because my left field of vision moved faster than my right field. The divider lanes on the left doubled at a 20 degree angle into my lane, causing me to get confused as to where my lane was. At night, the extra divider lane was not only at a 20 degree angle but it was sometimes elevated above ground. If you've ever had to drive with an eye closed, you know how hard it is.
I couldn't look down when descending a staircase because the end of the step would also double at a 20 degree angle, making it hard for me to see where the end of each step was. Other lines, whether they be on sidewalks or my kitchen floor, would double or be distorted.
Problem: After another pair of glasses which also were wrong, the Sears optometrist compared my developmental optometrist's original prescription with what was entered into the computer.
My doctor, on May 15, had prescribed a PD of 60 mm. Stephanie, the Sears optician, following "standard operating procedure" for Sears Optical, measured my PD per each eye with a measuring device (pupilometer?), and came to a total PD of 56mm. She overrode my doctor's PD calculation and entered her PD measurement into the computer prescription. The missing 4mm in the PD altered the horizontal prism in the glasses and made my life extremely difficult.
Those 4mm could have caused a car accident because of my distorted vision.
Blood boiling, I had to call their Sears Optical's corporate headquarters in Ohio to rectify this matter as the local store treated me like garbage. Luxottica owns Sears Optical, Lens Crafters and Pearle Vision. After I put up quite a fight, including threatening them with a medical malpractice lawsuit, they reimbursed me for my various doctor's office visits because of the incorrect glasses and are paying me for damages as I've lost two months of my VT. Unfortunately, Sears Optical didn't take me seriously until I told them that I had discussed the issue with an attorney.
If this happens to you and the optician and optician's supervisor don't treat you with respect and reimburse you for your visits, you can tell them that you will report their mistake to the Medical Board, the state agency which issues licenses for opticians and optical dispensaries. The words "medical malpractice lawsuit" tend to make people return your phone calls.
Impact on strabismics and amblyopes:
Sears Optical says they've informed their optician trainers about the issue. (Their legal department is also aware as they are handling my case.) But I will never find out if the opticians will indeed ever get any training on how to measure the PD for strabismics. An estimated 5% or so of the population has misaligned eyes. Since not everyone in the general population requires corrective lenses, but almost all strabismics and amblyopes do, more than 5% of any optical store's potential clients have my condition and could be at risk of causing accidents if wearing glasses that are incorrectly measured by opticians. If Luxottica doesn't train its staff right, I wonder about all other opticians in the country. Could they all be incorrectly measuring PD and dispensing harmful glasses?