The way the system displayed images was not by LCDs, as some would think. At the time, LCDs could not be used because they had two problems when they were first tested on the console: they would blur if anything moved on the screen, and users would see double instead of depth. Instead, a vertical line of 224 very bright, but very small, LEDs were used for each eye. These LEDs flashed on and off very fast in certain patterns. This line of LEDs was then magnified by a lens, and a vibrating mirror would reflect each line at a certain time into each eye, creating a full image due to the human eye's persistence of vision. Unfortunately, due to the quick flashing of the LEDs, many users felt sick, became dizzy, or had headaches after playing for a long time. To help this, an "automatic pause" feature was added, which stopped the game play every 30 minutes for the player to rest his or her eyes.