Blue field entoptoscopy (BFE) has been described as an effective method for evaluating macular function in patients with dense cataracts. We evaluated 150 preoperative cataract patients with BFE, and found the commercially-available instrument (MIRA BFE 100) to be accurate in patients with 20/400 or better preoperative acuity. There was a high percentage of false negative BFE results in patients with dense cataracts, and light flash VER testing was found to correlate better with attainable postoperative acuity in these patients.