The one thing that matters most: UV400
Sunglasses serve a functional purpose beyond fashion: they protect your eyes from ultraviolet radiation. A dark lens that does not filter UV is worse than wearing no sunglasses at all — the pupil dilates in response to the reduced visible light, which admits more UV than would enter an unprotected eye. UV400 means the lens blocks all UV wavelengths up to 400 nanometres, which covers both UVA and UVB.
Most listings on Chinese marketplace platforms for sunglasses at any price point above a few dollars claim UV400 protection. Whether this claim is accurate cannot be verified from a photo. For sunglasses you will wear regularly in bright sunlight, the UV400 claim in the listing is the minimum requirement. For buyers who want certainty, testing with a UV meter or purchasing from a listing with verifiable quality standards is the more reliable approach.
Lens quality: clarity and color
Beyond UV protection, the optical quality of the lens determines how clearly you see and whether the lens introduces distortion. In photos, a good lens looks clear and optically flat — it does not show the curved distortion of a cheap moulded lens when photographed at an angle. Tiny bubbles, streaks or inconsistencies in the lens surface are visible in close-up photos and indicate poor manufacturing.
Polarized lenses, which reduce glare from reflective surfaces, are available in many listings and are stated in the description. Polarization can be checked with a phone screen — a polarized lens held at 90 degrees to a phone screen will darken significantly. Ask the seller to perform this test and photograph the result if you need confirmation before ordering.
Oakley-style sport sunglasses
Oakley-style wraparound sport sunglasses are one of the most popular categories in the spreadsheet. These require specific lens geometry — a wide, curved shield lens or multi-piece sport lens design — and frame construction that allows for secure face fit during physical activity. The key quality indicators are lens curvature consistency, frame rigidity and nose pad comfort.
In photos, check that the lens surface is smooth and evenly curved with no flat spots or waviness. The frame should look rigid rather than flexible in the arms. The nose pads on adjustable versions should be symmetric and correctly positioned. Temple grips, if present, should contact the listing at the same position on both sides.
Frame materials
Sunglass frames on Chinese marketplace listings use a range of materials. Acetate frames are durable, warm and available in a wide range of patterns and colors. Acetate has a slight translucency that is visible in photos. Plastic injection-moulded frames are lighter and cheaper. Metal frames are available for classic shapes and vary in weight and corrosion resistance.
For sport sunglasses, a lightweight TR90 nylon frame is common and appropriate — it flexes slightly without breaking, which is an advantage in active use. For dress sunglasses in classic shapes, acetate or metal is the right material. The listing should state the frame material; if it does not, judge from the visual character of the frame in the photos.
Sizing sunglasses
Sunglass sizing uses three measurements: lens width, bridge width and temple length, written as something like 55-18-145. Most adults fall into a similar range for temples and bridge, but face width varies significantly. A wide-face buyer in a narrow frame will have the temples grip the head; a narrow-face buyer in a wide frame will find the glasses slip.
Compare the listed lens width and bridge width against a pair of sunglasses you own that fit well. The listed measurements usually appear in the product specifications even when they are not highlighted in the main description.
QC checklist for sunglasses
Check both lenses for clarity and visual consistency from the front and at an angle. Check the hinge action by requesting a photo with the temples both open and folded — smooth hinges with equal resistance are a quality indicator. Check that nose pads are symmetric and level. For wrap-style sport sunglasses, check that the lens sits evenly in the frame with no gaps or misalignment at the lens edge.