IsMyLcdOK is a pretty curious application that will check the screen to find those points. Sometimes, the warranty of the product include a term about the number of pixels that have to be malfunctioning to be covered by the warranty.
This means we recommend you to check the performance of your screen before the warranty period ends in order to save money.
How do you check the screen? IsMyLcdOK is the application you need because it offers a simple and comfortable way to do several tests in order to detect dead, paralysed and stuck pixels.
The tests are quite strange based on colors, gradient and stripes but they are really useful. In fact, those tests are quite good to solve some problems in case of stuck pixels.