What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Taking some medicines, such as stimulants (including caffeine),
depressants,
, and medicines to help vertigo.
- Too many movements of the head or other eye movements, such as
blinking.
- Not being able to do what is asked during the test. Medical
conditions that affect attention, poor eyesight, or cause sleepiness can affect
the test results.