Are cloudy patches on a gray LCD screen serious?

Slight LCD clouding visible only on uniform gray test images can be common. Judge it at your normal brightness, distance and room lighting. Large central patches that remain distracting in documents, videos or games are more reasonable grounds for contacting the seller.

Screen Clouding Test — LCD Brightness Uniformity

The short answer

Clouding is most common on LCDs: as the backlight passes through the panel, gray images show hazy bright and dark patches. It is related to backlight bleed, but looks more like broad clouds than bright edges. On many units it is clear only on uniform gray test images and nearly invisible on normal web pages or video. A browser helps reveal the pattern but cannot define one universal pass/fail threshold.

Use a real-world standardJudge the screen with your normal content and viewing distance. A mild patch visible only in tests is often acceptable; a large central, high-contrast patch that affects reading or viewing is more worth discussing with support.

Compare the pattern

In a moderately dark room, display mid-gray or light gray and view the screen straight on from your normal distance. Clouding can change with angle and may look stronger from the side. Cameras easily overexpose the effect, so do not rely on one photo. Also rule out protector bubbles, dirt and window reflections.

IPS glow changes strongly with viewing angle and distance. Backlight bleed tends to stay near the edges. Clouding looks more like brightness variation across the center or a broad area. OLED panels do not have traditional backlight clouding, though they can show low-gray tint or uniformity differences that require different interpretation.

Step-by-step test

Remove a bubbled protector, clean the screen and avoid direct strong room light.
Open the screen uniformity test and inspect mid-gray and dark gray straight on for 30–60 seconds.
Return to normal documents, browser pages and video to see whether the same area remains distracting.
Record the patch location, brightness setting and effect on text. If needed, capture video rather than relying on one overexposed photo.

When to contact support

For a new device, request inspection during the return window if a large obvious patch appears near the center at a normal viewing distance, brightness visibly fluctuates, or unevenness seriously affects films and games. Many brands do not treat mild clouding visible only on test images as a defect, so rely on written warranty standards.

For bright edges, see the backlight bleed guide. When shopping, use the office monitor buying guide and inspect gray uniformity in person when possible.