Ans. D: Dark room test To evaluate a patient with a strong predisposition for glaucoma, the provocative dark room or dark adoption test is performed. In this test, patient is placed in a dark room for 60-90 minutes and eye pressures are measured at regular intervals. If there is a tendency for developing closed angle (or narrow angle glaucoma), eye pressure may rise during the procedure assisting in evaluating the status. The fact that the darkroom test frequently fails to provoke a rise in ocular tension, even where there are symptoms of glaucoma, underlines the fact that, although a positive result is of great significance, no reliance should be placed on a negative darkroom test in the diagnosis of closed-angle glaucoma.