There are three levels of technical personnel in ophthalmology:  ophthalmic assistants, ophthalmic technicians and ophthalmic technologists.  They work under the supervision and direction of an ophthalmologist to perform ophthalmic clinical duties. 

• Assistants are trained to take medical histories, change eye dressings, administer some eye medications and perform routine vision testing. 
• Technicians perform duties such as taking optical measurements or external ophthalmic photographs, instruct the patient in care and use of corrective lenses, provide limited assistance in an ophthalmic surgery; and maintain ophthalmic surgical instruments as well as office equipment. 
• Technologists are trained for additional duties, such as taking ophthalmic photographs, using ultrasound, as well as providing instruction and supervision to other ophthalmic personnel.  Ophthalmic technologists are expected to perform at a higher level of expertise than ophthalmic technicians and to exercise considerable clinical technical judgment.

Areas of Specialization
Certified assistants, technicians and technologists often develop their own skill specialties as new techniques are put into practice.  With additional training, an ophthalmic technician may become an orthoptist specializing in the evaluation and treatment of patients with crossed eyes and related muscle imbalances of the eye.  Some programs offer this special emphasis during the second year of the ophthalmic technology training. 

Work Environment
Ophthalmic assistants/technicians/technologists are employed primarily by ophthalmologists and may be involved with patients in any setting for which the ophthalmologist is responsible.  They may also work in medical institutions, private offices or in research laboratories.  Typically, assistants, technicians, and technologists work a standard 40-hour week and may put in overtime as needed.