It works best when you have many frames and few on-face photos.
Eyewear stores often carry dozens or hundreds of frames, and booking a model for each one is expensive, so usually only the bestsellers get on-face images while the rest show a packshot that makes size and style hard to judge.
With the AI glasses try-on you can give every frame an on-face image for the product page and listings, and show the same frame on different ages, genders and skin tones.
Once you know which frames lead the collection, spend the shoot budget on those. When you upload a portrait, use only your own photo or one you have permission to use, never a public figure.
The preset faces are fictional people made for product images. Front-facing, evenly lit portraits with eyes and ears visible give the steadiest results.
Before a result goes live, check four things in order: the frame outline and rim thickness, the lens tint or clarity, the bridge and both temples, and the face itself.
If any of them is off, keep the glasses photo loaded, pick another face or add a short note, and generate again. Testing two or three frames first keeps a whole collection consistent.