Weird Cracks on Eyeglass Lenses

Weird Cracks on Eyeglass Lenses

by Brian Chou, OD, FAAO, FSLS

  • January 5, 2021


Weird Eyeglass Scratches

Eyeglass lens crazing. Photo courtesy of Marisa Chung, O.D., F.A.A.O.

Your new prescriptive eyeglasses lenses suddenly have weird looking scratches.  They look like cracks, ripples, or wrinkles. Yet you know for sure that the lenses did not get scratched and you cannot clean them off.  How could this happen when you have dutifully kept them in your car?  After all, you use them just for driving.  You even paid extra to get an anti-reflective treatment to make the lenses look extra clear.


Lens Crazing is Pretty Crazy!  What Causes the Weird Cracks?

Your lenses most likely have experienced lens “crazing”, a common problem especially during the summer.  It is caused by expansion of the anti-reflective treatment due to heat at a different rate from the underlying lens material.  As any dog owner knows, the interior of your car can experience significant temperature increases.  For example, if the outside air temperature is 85 degrees Fahrenheit, the interior of the car can increase to 130 degrees Fahrenheit in an hour. Repeated and extreme cycles of heating and cooling for a spectacle lens can cause crazing.  In turn, lens crazing can create glare and degrade your vision, making streetlights at night have a soft glow around them.

Prevent Lens Crazing by Taking Eyewear With You

Although your car may have a built-in eyewear holder in the overhead console, the best practice is for you to keep your prescriptive eyewear with you in a handbag or eyeglass case.  That way, your eyewear is not subjected to potential temperature extremes inside your car, and you can prevent weird cracks on your eyeglass lenses.  Even so, most reputable eyeglass sellers offer some type of warranty on their prescriptive eyeglass lenses with an anti-reflective treatment.


To fill your new eyeglass prescription in distinctive eyewear, schedule an appointment with our American Board of Opticianry certified optician at ReVision Optometry today.


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