Visual Electro-Diagnostic Clinic

22 Sanders St

Upper Mt Gravatt

Patient Information- visual tESTS


Visual tests performed at the Clinic (VEP, ERG, EOG, PERG, AVEP, MFERG & COLOUR VISION) are elective tests that look at the way your visual system is working in order to help with the diagnosis of any visual problem and possibly to guide towards appropriate treatments.

The tests will take between one and four hours. You will have drops put into your eyes to dilate the pupils. Electrodes will then be placed on your head and face to monitor the working of different types of visual signals, usually checkerboard patterns or flashes of light and to record these responses. For part of the time you may be sitting in a very dark room. In some parts of the test very fine silver thread electrodes will be gently placed onto the surface of the eye. This won’t be felt because of the eye drops which have numbed the eye. Fibre Electrodes for ERG Skin Electrodes for Child ERG

Electrodes and screen for VEP

Complications with these tests are very rare, but it is possible to have a reaction to the eye drops, causing some redness, or sore eyes. Very rarely patients have been known to faint. Micropore (adhesive medical tape) can cause irritation to sensitive skin and very rarely, people react to the placement of the very light electrodes onto the eye. You should alert the clinic if you have known allergies or have had a reaction to electrodes before.

Because your eyes will be dilated, you will have temporary sensitivity to light after the tests and your vision may be “blurry”.

*It is necessary to organise a driver to pick you up as your vision will remain blurry for several hours after testing

*Please do not wear face creams or makeup on the day

*All current glasses should be brought with you

*Contact lenses should not be worn

*Sunglasses are advised for after testing as your eyes will be glare sensitive due to the dilation

*For infants: it is suggested that you bring along a bottle and some favourite toys to help calm them. 


Your eyes may feel irritated up to an hour after testing. If persistent problems occur, please phone the Clinic 07 34204899

or email: This email address is being protected from spambots. You need JavaScript enabled to view it.