VISX Laser 3D ActiveTrak Without a tracking device, laser eye correction requires patients to hold their eyes as still as possible during laser eye surgery. However, even a "still" eye makes minute, involuntary movements—including moving slightly with each breath. Now, the VISX 3D ActiveTrak follows the tiny motions of your eye instantaneously and automatically, in all three dimensions, repositioning the laser to ensure accuracy. The ActiveTrak System is the only laser system that can capture all three dimensions of intra-operative eye movements without the requirement of pupillary dilation. At last, you can relax during your laser eye surgery, knowing that you're obtaining a vision correction that's precisely centered on your eye. Relax with 3DActiveTrak.