If I put glasses on will Face ID recognize me?

I have an iPhone XS and I wear glasses all the time. My FaceID works just fine with glasses on or off, including my polarized & partial mirror coated prescription sunglasses (black frame RayBan new wayfarer frames).

About Face ID advanced technology - Apple Support

”Face ID automatically adapts to changes in your appearance, such as wearing cosmetic makeup or growing facial hair. If there is a more significant change in your appearance, like shaving a full beard, Face ID confirms your identity by using your passcode before it updates your face data. Face ID is designed to work with hats, scarves, glasses, contact lenses, and many sunglasses. Furthermore, it's designed to work indoors, outdoors, and even in total darkness.”

Not sunglasses.

If the frame of the glasses is light, there should be no problems.

And remember that you can always add an alternate appearance, so Face ID still recognizes you.

Regards

Giulio