Strokes can come on suddenly. According to the Centers for Disease Control (CDC), they are a medical emergency that happens when the blood flow to the brain is interrupted, causing a lack of oxygen leading to brain damage, long-term disability, or death. Knowing what the signs are to watch for beforehand may make all the difference in treatments and recovery — most especially since time is of the essence with strokes. The best outcomes typically occur when a stroke — sometimes called a “brain attack” — is identified within the first three hours of onset.

One possible early warning sign of an impending stroke is ocular migraines. These are often temporary and painless vision disturbances that may last for a few minutes up to an hour before your vision returns to normal. These disturbances can include a pulsing-light, pixilation, or kaleidoscope/prism effect with your vision and may happen prior to a migraine headache. Ocular migraines happen in both eyes and, while alarming, are not necessarily a cause of concern (although, mention it to your eye-care provider at your next comprehensive eye exam).

But if the ocular migraine happens in just one eye, are increasing in frequency, or are accompanied by your vision darkening for a period of time, that’s your signal to get to the doctor to determine if it’s truly an ocular migraine or an indicator of something more serious, like a stroke. Your eye-care provider will dilate your pupils and get a good look at the back of the eye, where blood vessels and nerves can detect abnormalities in the body. Many issues can be detected with an eye exam before they become major problems like hypertension, diabetes, high cholesterol, thyroid issues, sexually transmitted diseases, and Alzheimer’s.

If your vision suddenly changes and you experience the following BE FAST symptoms, call emergency services (911) or get to the emergency room:

  • Balance (loss of coordination)
  • Eyes (vision changes in one or both eyes)
  • Face drooping (one side)
  • Arm weakness (one side)
  • Speech difficulty (sudden slurring)
  • Time to call emergency services (911)