I'm going to copy and paste a bit off the internet here as we don't actually deal with any treatment, that would be an ophthalmologist who would be doing it!
Here's what I can tell you:
"The type of laser treatment used to treat diabetic retinopathy is called photocoagulation.
A course of photocoagulation usually involves one or more visits to a laser treatment clinic. An ophthalmologist will carry out the procedure, which is usually available on an outpatient basis. This means you will not have to stay in hospital overnight.
Before the procedure, you will be given a local anaesthetic to numb the surface of your eye, as well as eye drops to widen your pupils. A special contact lens will be placed on your eye to hold your eyelids open and allow the laser beam to be focused onto your retina.
Small laser beams will be aimed at the damaged area of your retina. These will seal any blood vessels that are leaking and destroy any abnormal blood vessels that have grown in your retina.
Photocoagulation is not usually a painful procedure but you may feel a sharp pricking sensation when certain areas of your retina are being treated.
If you have had laser treatment in the past, you may experience some discomfort during the treatment. If you do, your doctor may give you stronger painkillers or a mild sedative.
After the procedure:
After laser treatment, your vision may be blurred. However, it should return to normal after a few hours.
Your eyes may also be more sensitive to light, and some people wear sunglasses until their eyes have adjusted.
You will not be able to drive after having laser surgery, so ask a friend or relative to drive you home or take public transport.
If you have had previous eye treatment, your eyes may ache afterwards. Over-the-counter painkillers, such as paracetamol, should help.
Photocoagulation can sometimes affect your night vision and peripheral vision (side vision).
Over 50% of people who have laser treatment for diabetic retinopathy notice some difficulty with their night vision, and 3% experience some loss of peripheral vision."