The short answer
Start with the printing on the inside of the temples (the arms), then check the lenses, hinges, materials and accessories, and finally the seller. Genuine frames from major brands usually carry a model number, color code and size that match an official listing. Counterfeiters copy these details too, so a matching number is a good sign, not proof. If you are spending real money, buy from an authorized retailer or have the pair checked by the brand or an optician who handles that brand.
1. Read the temple markings
Open the frames and look at the inside of both arms. Many designer brands print:
- Model number: a code for the frame style.
- Color code: a code for the frame and lens color combination.
- Size: usually lens width, bridge width and temple length in millimeters, such as 52□18 140.
- Country of manufacture and conformity marks: for example a CE mark on many pairs sold in Europe.
Search the model and color code on the brand's own website or an authorized retailer's listing. The shape, color and lens type should match. Printing on genuine frames is usually crisp and even; smudged, crooked or misspelled text is a common sign of a fake. A model or color combination the brand never made is a strong warning sign.
2. Check the lenses
- Etched logos: some brands etch a small logo or initials into a lens near the hinge. Ray-Ban, for example, is known for a small etched mark on many of its lenses. Check whether the brand and model you have should carry one, and where.
- Printed logos: logos on the lens surface should be sharp and evenly applied.
- Optical quality: look through the lenses at a straight line, such as a door frame, and move them slowly. Noticeable warping or distortion is a warning sign.
- Polarization: if the pair is sold as polarized, look at a phone or computer screen and tilt the glasses. Many polarized lenses make the screen darken at certain angles. This only tests polarization, not authenticity.
3. Feel the hinges and materials
Genuine designer frames usually have sturdy, smoothly moving hinges, often metal with neat screws, and an even finish without rough seams. Fakes may have loose or squeaky hinges, glued parts and plastic that feels light, flexible or brittle. Weight alone is not proof: some genuine models are deliberately very light.
4. Look at logos and details on the frame
Compare the logo plates, engravings and any decorative details with official photos of the same model. Look at spacing, font, alignment and how the logo is attached. Uneven gaps, slightly different shapes and logos that are stuck on rather than set in are common signs of a copy.
5. Examine the case and paperwork
Many genuine pairs come with a branded case, cleaning cloth, booklet and sometimes a certificate or authenticity card. Check printing quality, stitching on the case and logo consistency. These extras are frequently copied, and genuine secondhand pairs often lose them, so they support a judgment but do not decide it.
6. Watch for seller red flags
- "New" designer sunglasses at a fraction of the usual retail price.
- Many identical pairs from one seller, especially in unusual color combinations.
- No photos of the inside of the temples or the lens markings.
- Listings that say "inspired by", "style" or "replica" in the details.
- Pressure to pay outside a platform with buyer protection.
Safety note
Counterfeit sunglasses may not provide the UV protection they claim. If you are unsure, an optician can test UV protection, and that is worth doing for any pair you plan to wear, genuine or not. If you are selling, mention any scratches on the lenses and whether the original case and paperwork are included.
Where WorthAI fits
WorthAI can help you identify the likely brand and model from a photo and see what similar pairs sell for, with the listings behind the estimate. The estimate assumes the sunglasses are genuine. WorthAI is not an authentication service, so check the markings and build yourself and ask the brand, an authorized retailer or an optician for an opinion on valuable pairs.
Frequently asked questions
Where is the model number on designer sunglasses?
On many pairs it is printed on the inside of one of the temple arms, often with the color code and size on the other arm.
Do all genuine Ray-Bans have an etched logo?
Many Ray-Ban lenses carry a small etched mark near the hinge, but check what is expected for your specific model. Its presence alone does not prove a pair is genuine.
Do fake sunglasses protect your eyes?
Not always. Some counterfeits may not offer the UV protection they claim. An optician can test the lenses.
Can WorthAI authenticate sunglasses?
No. WorthAI identifies the likely model and estimates what similar genuine pairs sell for. It is not an authentication service.