Pre-screening consists of a series of tests which are performed on every patient before consulting with the ophthalmologist. These include an assessment of visual acuity, pressure and refraction (a glasses test).
Uncorrected vision is assessed using a chart of letters (Snellen Chart) which is read from a distance of 6 meters. An objective refraction is then performed using a special machine that estimates your spectacle prescription. If you already have a pair of spectacles, we also measure the prescription of your current spectacles and compare it to your latest test. Your corrected vision is then tested with both your spectacles and your objective refraction. The final step of pre- screening is a test of intraocular pressure which is measured using an air puff device or a handheld tonometer (icare). The results of pre-screening may guide us to perform additional special investigations before you consult with the ophthalmologist.
The purpose of a pre-screening assessment is to reduce the overall time spent in the ophthalmologist’s office and thus make your visit as quick and convenient as possible.