There has been a mounting body of evidence that removal of the crystalline lens can result in a lower pressure. The effect is greater for narrow angle glaucoma or chronic angle closure glaucoma than open angle glaucoma but on average with open angle glaucoma the pressure drops on average 2-4 points. The higher the baseline, the greater the drop. Some of this effect may be due to the phenemenon of “regression to the mean”. At this time, it is reasonable with early or mild glaucoma and visually significant cataracts to only remove the lens and not necessarily perform a combined glaucoma and cataract operation.