The I-Test Vision Screener

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The I-Test was invented in Norway by a GP who was involved in medicals for private pilot's licences. His main aim was to produce a means to offer those twin goals of any effective screening process - simplicity with accuracy.

Light and simple

The unit is a foldable head set (Figure 1) made of lightweight plastic. It is easily portable, weighs just 186g and measures 155mm by 125mm by 20mm when folded. Within each half is a rotatable lens rack containing hard-coated sphere lenses from -4.00 to +4.00DS in 0.50DS steps. By folding the unit over, the two lens racks work in unity to offer a range of -8.00DS to +8.00DS. There is also an occluder and a pinhole stop.