Fluorescent tubes, computer screens and many other screens flicker, but it happens faster than the human eye can perceive it.

However, it is just this flickering that causes a subconscious feeling of stress. In order to prevent a 50 Hz AC flickering, lights should be supplied with a high-quality electronic ballasat device (EB), since a conventional electronic ballast interrupts the lamp current at 50 Hz 100 times per second.

With the ScreenChecker, you can test to see if and how strongly an object in your vicinity flickers. Afterwards you can decide how you can best avoid this stress-causer.