Why One Pixel Can Spoil a Whole Screen
A screen image is built from tiny picture elements, or pixels. Each pixel usually contains red, green, and blue subpixels whose light combines to make the colors you see. In an LCD, liquid crystals control how much light from a backlight passes through each subpixel. In an OLED screen, the subpixels produce their own light.
A dead pixel is one whose display elements no longer respond properly, so it stays dark or fails to show the intended color. A pixel that remains lit in one color is often called a stuck pixel instead. The distinction depends on the display technology and the specific failure, but both can leave a conspicuous speck in the image.
Why the Speck Keeps Pulling Your Eye
The flaw is tiny, but it sits inside a carefully arranged field of color and detail. If its brightness or color sharply differs from the surrounding image, it creates a local contrast the eye can notice—especially against a uniform background such as a bright sky or a blank document. Once you know where it is, your attention can keep returning to that spot, making it seem more prominent than its size suggests.
That is why a screen can look flawless at a glance and then become a pixel-hunting exercise. The image has not changed; your eye has learned exactly where the mismatch is.
