Before the test, a technologist will obtain a thorough history. The patient will then be asked to read an eye chart to determine their visual acuity. 

The patient’s head will be measured, marked and five electrodes will be applied to the scalp. In most cases, the electrodes are applied with a special tape that is easily removed when the test is finished. 

Once the electrodes have been applied, the testing can begin. The patient will be asked to sit in front of a monitor and carefully watch an alternating pattern of squares.  

The electrodes on the patient's scalp record how the brain processes this stimulation. Waveforms recorded by a computer reflect this activity. 

When the test has been completed, the patient’s scalp is cleaned. 

Patients who wear reading glasses or contact lenses should bring them for the study.

Continue taking medication as normal. Please bring a list of current medications. 

Sleep well prior to the testing. It’s important to not be sleepy for the VEP.

Fasting is not required, in fact, eating a meal or a snack prior to the test is advised.

Patients do not need to refrain from consuming caffeine products such as coffee, tea or soda. 

Do not consume alcohol 12 hours before testing.