Optometrists specialise in visual defects of the physiologically healthy eye.

They are able to prescribe spectacles or contact lenses to rectify or alleviate visual defects such as far-sightedness, short-sightedness, astigmatism (image distortion) and presbyopia (far-sightedness as the result of age).

They may prescribe corrective eye exercises or other treatment not requiring drugs or surgery. They may also give advice on environmental factors which affect visual efficiency. They evaluate the specific needs, working demands and hobbies of their patients in order to prescribe the most suitable correction.

Optometrists should not be confused with ophthalmologists or dispensing opticians. Ophthalmologists are physicians who perform eye surgery, and diagnose and treat eye diseases and injuries. Like optometrists, they also examine eyes and prescribe spectacles and contact lenses.

Dispensing opticians fit and adjust spectacles and may fit contact lenses according to prescriptions written by ophthalmologists or optometrists.

Should optometrists detect any disease or pathological abnormalities in the eye, they refer patients to an ophthalmologist (eye specialist or surgeon) for medical treatment. In addition, optometrists consult with educators on preventive vision care for school children, and with public officials and management to help eliminate vision hazards.

Optometrists promote eye hygiene and general eye safety, and also inform people about correct reading habits and lighting.

This area, known as preventative or environmental optometry, forms an important part of their work. Optometrists are also consulted by institutions to develop vision-training techniques for enhancement of specific visual skills.

One such technique is speed-reading, a programme utilised by many tertiary educational institutions.