The first thing to check is the overall quality of the product. Note errors in grammar and spelling, and check to see if something is printed. Also check the paint and wear. Make sure the paint is intact and not chipped.
2. Nose Piece
Next, the nose piece should have the Prada logo.
Recently, the Prada trademark is typically stamped on at least two temple pieces on the insides of Prada sunglasses with adjustable nose bridges. A detail many counterfeiters do without is that most consumers gravitate toward the outer details and overlook the inner details. So, when you are evaluating the legitimacy of Prada sunglasses, make sure you pay particular attention to the nose piece.
Raise your arms and make sure that the prints are centered. Many real ones can appear slightly off-center, but they should be close to the center.
Next, evaluate the Prada logo, the 'Made in Italy', and the CE icon on the right arm. Following this, the Prada logo must be in just the right place; up at the top.
There are two major differences between the Prada or fake here, and the quality of the stamp. Typically, the counterfeiters make low-quality screen prints of the Prada logo and text. The screen-print method provides no texture to the logo, whereas authentic pair of Prada glasses provides a texture in the plate.
A simple check that if to see if you purchase fake Prada glasses is by running your finger over the stamp - if you have a fake pair, you won't feel anything. On a genuine pair of Prada glasses, you should be able to feel the texture or some form of indentation.
Before buying eyeglasses, be aware that extremely inexpensive glasses are often low quality. An authentic pair of Prada eyeglasses will cost approximately $150 without lenses and a pair with platinum frames will cost as high as $400 or more. If the discounted price is significantly lower than the original cost, it could be possible the glasses are fake.
In addition, inside each pair of glasses, the majority of Prada glasses have their serial number etched onto the right lens and the Prada logo etched onto the left lens in smaller fonts.
7. Warranty Card
Ask the seller for the certificate of authenticity. This should have the Prada brand name and information about the materials used in the eyeglasses. Check to make sure the certificate states "Made in Italy." The paperwork included with the eyeglasses should also have a warranty issued from Prada.
Prada glasses are usually sold with a carry case, cleaning cloth & warranty card. Before purchasing a pair of Prada glasses, be sure to request a certificate of authenticity.
If the glasses are purchased from a private individual and do not have the included warranty card and certificate of authenticity, it is still possible that the glasses is fake.