What's the Difference Between a Sight Test and an Eye Examination?

Sight Test

A sight test is really just what it says... it is a test of how well, or not, a person can see, and a measurement of any corrective prescription that could be used to give someone the best vision possible. A sight test could involve additional tests such as visual fields and eye pressures but may not always detect underlying conditions requiring deeper investigation. A ‘sight test’ is just one part of a more comprehensive ‘eye examination’.

An eye examination is a series of tests performed by an ophthalmologist (medical doctor), or an optometrist, assessing vision and ability to focus on and discern objects, as well as other tests and examinations pertaining to the eyes. Health care professionals often recommend that all people should have periodic and thorough eye examinations as part of routine primary care, especially since many eye diseases are asymptomatic.

Eye examinations may detect potentially treatable blinding eye diseases, ocular manifestations of systemic disease, or signs of tumours or other anomalies of the brain.

Ideally, the eye examination consists of an external examination, followed by specific tests for visual acuity, pupil function, extraocular muscle motility, visual fields, intraocular pressure and ophthalmoscopy through a dilated pupil.

A minimal eye examination consists of tests for visual acuity, pupil function, and extraocular muscle motility, as well as direct ophthalmoscopy through an undilated pupil.

Close inspection of the anterior eye structures and ocular adnexa are often done with a slit lamp which is a table mounted microscope with a special adjustable illumination source attached. A small beam of light that can be varied in width, height, incident angle, orientation and colour, is passed over the eye.