Why does Cannabis make your eyes red?

Why does Cannabis make your eyes red?

April 26, 2017


Every day, millions of internet users asks Google what are seemingly simple questions about Cannabis. However, because ‘the powers that be’ deem cannabis to a controversial topic the internet is rife with misinformation, bias and propaganda.

DANK is setting out to fix this by answering your most pertinent questions whether it be about herbs, edibles or Dry Herb Vaporizers UK.


Caught Red-Eyed?

Alongside a big smile and a serious case of the munchies, red bloodshot eyes are one of the major giveaways that you have had a good session with your dry herb vaporizer.

You may have read that red dry eyes occur when someone is allergic to the cannabis smoke in the air. However, this does not explain why eyes can go red after eating edibles.

Also, you may have noticed that it doesn’t happen every time or that some people’s eyes turn red after one toke whilst others can session for hours and with no effect on their pupils at all.


Unwelcome but harmless?

Red Eyes are actually a result of everybody’s favourite active ingredient – THC. When THC is absorbed into the body it causes the blood vessels and capillaries to dilate. The eyes, in particular, have tens of thousands of capillaries and when these dilate it means more blood flows through the eyes giving the appearance or red eyes!

This effect is harmless for most individuals and is actually beneficial for sufferers of Glaucoma. Whilst, THC will not cure Glaucoma but it can help a sufferer manage their symptoms and lead a normal life.



Just because red eyes are harmless it doesn’t mean they are welcome! Luckily there are a few simple steps to help alleviate red eyes.

Eye drops, are great to moisten dry eyes

Use a strain of cannabis low in THC or even consider switching to CBD E Liquid. Strains high in CBD, for example, will have a far less effect of your eyes.

Stay hydrated. Always good advice whether you are using cannabis or not but if you are drinking plenty of water you are less likely to suffer from dry uncomfortable eyes!