Vision Screening Why? Tools of the trade
Why? 1. Law 1.Vehicles (cars & heavy duty) Regulation 102 of the National Road Traffic Act (93 of 1996) 2.Driven machinery Driven machinery regulations (Feb 2005) of the Occupational Health & Safety Act
2. Employee productivity –Clear & comfortable vision –Headaches, neck aches Why?
Regulation 102 of the National Road Traffic Act (93 of 1996) Codes A1 to EB (light vehicles): 6/12 in each eye One eye worse than 6/12, other 6/9 or better Codes EC & EC1 (heavy duty vehicles): 6/9 in each eye One eye worse than 6/9, too bad… Minimum visual acuity
Regulation 102 of the National Road Traffic Act (93 of 1996) Minimum visual fields Codes A1 to EB (light vehicles): 70° temporal each eye One eye < 70°, at least 115° total horizontal field (both eyes together) Codes EC & EC1 (heavy duty vehicles): 70° temporal each eye One eye < 70°, too bad…
Driven machinery regulations Same as for codes EC & EC1 (heavy duty) –6/9 each eye –70° temporal visual field each eye PLUS Stereopsis (3-D vision) Existing PDP –Same as codes EC & EC1 (no stereopsis required!)
Tools of the Trade
All-in-one vision screeners Keystone vision screener Keystone Telebinocular
All-in-one vision screeners Pro’s Visual acuity (far & near) Stereopsis Colour vision Muscle balance
All-in-one vision screeners Cons Patient observation more difficult, eg. squinting or viewing through incorrect part of spectacles Stereopsis test difficult to explain Proximal accommodation
Tools of the trade Visual acuity Snellen chart 1800’s – stood test of time Wall chart Chart projector
Correct use!! Test distance see ‘Eye Care Topics → Visual Acuity’ on Gentle eye cover Watch person for cheating Snellen chart
Colour vision Ishihara plates -Simple
Colour vision Farnsworth D-15 Good adjunct to Ishihara
Stereopsis Randot stereotest NB presbyopes to wear near vision correction
Autorefractor Refractive state of eye Keratometry –Measures basic corneal curvature
Non-contact tonometer Intra-ocular pressure Glaucoma Peripheral field loss
Thank you