The term laser is an abbreviation for Light Amplified by Stimulated Emission of Radiation. The laser is a powerful electric current passed through a tube containing either Argon gas or Neodymium YAG. Energy is produced and the laser emits a narrow uniform light beam which when focused through a microscope can open a drainage pathway through the iris.

The laser allows patients to be treated with no risk of infection, in a relatively painless way on an outpatient basis. The opening in the iris allows fluid to move toward the drainage meshwork of the eye more easily.

In some cases it is necessary to also do laser treatment to the drainage meshwork for further lowering of the eye pressure (this is called Argon Laser Trabeculoplasty).