Laser guided fixation system and method for assuring alignment, constant pressure, and stationary positioning during ultrasound measurement of the eye: The invention employs a stable multi-purpose platform that carries a prior art ultrasonic probe used to measure the axial length of the eye, a projected laser spot as a fixation device, a gravity dependent swing arm with dual levels to maintain constant orientation and adequate pressure on the eye during measurement and a headpiece which keeps the entire apparatus stationary in relation to the patient's head. The method for using the invention describes a protocol which results in accurate and reproducible axial length measurements by establishing a means for assuring proper orientation, controlled pressure, and stationary positioning during axial length measurement of the eye.