The photo eyes contain two sensors, one on either side of the garage door, approximately 6 inches (0.15 m) above the ground. One of the sensors focuses the beam toward the other; if an object interrupts the beam, the sensor breaks circuit, blocking the door from closing. The sensors are fragile and can easily become misaligned. If your garage door goes up but does not close, or only partially closes then reopens, it also may make a clicking sound, or the garage light may flash a few times, these are indication that the photo eye needs adjustment. For your garage door service, Call Garage Door 4 Less at (651)797-8444 or book your service Call online today.