During photocoagulation, the ophthalmologist sits in front of the patient and uses a foot pedal to direct a powerful laser beam at the spots in the retina that must be treated. The patient then sees a brief flash of light. This process is repeated several times.  

Although the procedure is not typically painful, the patient may experience some stinging or discomfort. The procedure generally lasts less than 30 minutes. If scatter photocoagulation is performed for more advanced stages of diabetic retinopathy, two or more treatments may be required over several weeks.

After photocoagulation, the treated eye may be sore for a few days. Other side effects tend to be mild. Patients may experience several days of blurred vision after focal laser treatment or pan-retinal photocoagulation (PRP). After PRP, side (peripheral) vision can be reduced or lost, and the eyes will generally take longer to adapt to low light. Most patients can resume usual activities within a few days of the procedure.

Rarely, patients may experience bleeding inside the eye that can last for three or four months. This generally stops on its own, although most patients report residual small floaters (tiny specks in vision) that may disappear over a period of months. If eye bleeding does not cease, patients should contact their ophthalmologist, who may recommend vitrectomy (a surgical procedure in which small instruments and a microscope are used to remove blood and scar tissue from the eye). Full recovery from photocoagulation can take up to six months.