Dear Customer, thank you for contacting Firmoo. PD stands for Pupillary Distance, which is the distance between your pupils in millimeters. PD is very important for accurately fitting your lenses to achieve visual acuity. Generally, PD numbers do not change for adults. The average PD range for adults is 55-75 mm and for kids is about 42-55 mm. A difference of 2-3 mm is acceptable. Please kindly confirm with your eye doctor on the PD, or you can also measure it in this way https://www.firmoo.com/help-p-43.shtml to confirm. For any further questions or immediate assistance, you may also call our call center thru toll-free hotline at 1-855-487-6006 opens every day from 7 a.m.- 4 p.m. PDT. You can also contact us through our Live Chat Support Team: Start a live chat (Everyday, 4 a.m.-10 p.m. PDT.) or email us at service@firmoo.com. Please stay safe and healthy!

Hi Meira, For PD57mm, this frame also fits you but special lenses will be used since your PD is smaller than the minimum PD(59mm) of this frame. So I'm afraid another $10 will be charged about that. But you can choose other smaller frames if you don't want to pay such fee. For any problem, pls feel free to contact service@firmoo.com