I devised a new and simple method to measure the anterior chamber depth that requires only a Haag-Streit 900 slit lamp. Viewing the anterior chamber at 45 degrees and matching the height of the corneal slit beam to the depth of the anterior chamber enables the observer to calculate the anterior chamber depth by multiplying the measured slit height by 1.4 or, more accurately, by use of the table provided. The accuracy over the range of clinically encountered depths of the anterior changer is +/- 0.2 mm relative to standard pachometry.