Purpose: To test for visual acuity near and far, visual fields and colour blindness to ensure applicants have the minimum level of functioning to accomplish specific visual tasks.
Equipment: Hanks Near Vision Chart and Snellen Eye Chart
Who can complete: registered or enrolled nurse, doctor or trained allied health professional (occupational therapist, exercise physiologist, physiotherapist).
Time to complete: 5 minutes
Visual Fields:
Performed using either your fingers or a pen.
Both applicant and examiner’s head should be level (preferred in a sitting position).
Test each eye separately with glasses removed.
The applicant’s head should be at arm’s length from the examiner, and the eye not being tested should be covered with the palm of the applicant’s hand.
If the applicant’s right eye is being tested, the applicant should look straight into the examiner’s left eye.
The target (hatpin) is brought into the applicant’s visual field from four main directions, in a diagonal manner towards the centre of the field of vision. Superior temporal, superior nasal, inferior nasal and inferior temporal quadrants are examined.
The applicant is asked to identify when they first visualise the target and if it disappears throughout its range of motion.
The blind spot is also mapped out by noting the applicant’s subjective acknowledgement of the disappearance of the target (pinhead) around the centre of the field of vision for each eye. Compare the size of the applicant’s blind spot to your own and note it as being “normal” or “abnormal” based upon your judgement.
Record the applicant’s degrees of the visual field on the paperwork making notes if it is within the abnormal zone.
Strabismus is a condition where the eyes are not properly aligned to one another. This
condition is often a result of an imbalance or lack of coordination between the extra-ocular muscles. Typically, one eye will move in a typical pattern, while the other points in (esotropia or “crossed eyes”), out (exotropia), up (hypertropia) or down (hypotropia).
Colour Vision is tested with Ishihara colour plates first. If the applicant fails the colour plates, the tester can move straight to the Farnsworth Test and can be marked as abnormal.