Why Does Weed Make Your Eyes Red?

Published: July 16, 2022

Do you notice your eyes getting red every time you smoke weed? Red eyes are amongst the common tell-tale signs that someone has smoked weed. It’s certainly not a physical change you want people to notice when you are in public.

The good news is that there is a scientific explanation as to why your eyes turn red. Therefore, there may just be a solution to preventing your eyes from getting red when smoking weed. But, first, let’s find out why does weed make your eyes red.

Why Does Weed Make Your Eyes Red?

According to scientists, the smoke from weed is not what makes your eyes red. After all, even if you take weed without smoking, you may still notice your eyes turning. Instead, it is how THC reacts in your body.  When taken, the THC from weed lowers the blood pressure levels in your body. In turn, this causes the blood vessels and capillaries, including those around the eyes, to dilate.

As the ocular (eye) capillaries, blood flow to the eyes increases while reducing intraocular pressure. The increased blood flow, in turn, turns the eyes red and decreases intraocular pressure. In fact, this effect THC has on the eyes is exactly why it is used for treating glaucoma.

Additionally, this mechanism explains why the intensity of redness on the eyes varies based on the potency and amount of weed (THC) you intake. So, if you take small amounts of THC, you will notice zero changes to your eye color or very faint red eyes.

However, if you take a high THC strain, you are likely to have deep red eyes. Furthermore, the fact that THC affects the eye color rather than smoke explains why your eyes turn red even without smoking. So, if you consume edibles, you will still notice your eyes have turned red.

How To Do You Get Rid Of Red Eyes From Cannabis?

THC affects your eye color at the blood level. However, this doesn’t mean that you can’t counter red eyes from cannabis. Here’s how you can do so;

Choose the Right Strain

As the THC content in your cannabis increases, so does the intensity of the red color on your eyes. To prevent this from happening, you can always opt for a lower THC strain. Alternatively, you can opt for strains with a higher cannabinoid level (CBD, CBDN, etc.). This helps to keep the THC level at a minimum.


One of the best ways to keep the effects of THC is to keep the body hydrated. It is advised to drink water before, after, and when you are taking weed.  The same advice is extended for keeping your eyes clear. Drinking more fluids helps protect the eyes, mouth, and skin against dryness.

Eye Drops

If you already notice red eyes from consuming weed, you can reduce the intensity by using eye drops. Simply purchase over-the-counter eye drops designed to reduce eye redness. Alternatively, you can wash your face and eyelids with cold water.

But, the bottom line is the change in eye color after smoking weed doesn’t affect you physically apart from the appearance of your eyes. So, some weed users choose to do nothing about it. All you have to do is simply smoke your weed from the comfort of your home and sober up before you socialize. Alternatively, pick your favorite sunglasses and continue to enjoy your day.