Patients may also experience symptoms of dysphotopsia. The term dysphotopsia is used to describe a variety of visual symptoms that result from light reflecting off, or being blocked by the edge of the intraocular lens (IOL). Dysphotopsias are generally divided into two categories: positive and negative. Positive visual changes involve symptoms of glimmering, flashes, starbursts, haloes, or streaks of light, while negative dysphotopsias are perceived as shadows or dark areas in the visual periphery. Typically these dysphotopsias are seen as an arc in the outer or lateral area of vision. It is important to know that sometimes, despite a perfect surgery, a patient can experience positive or negative dysphotopsia. While there is no way to predict its onset, for most patients, it is fortunately a temporary issue. In the vast majority of cases, the symptoms subside within a few weeks after surgery due to the process of neuroadaptation.