Why Do Edibles Cause Red Eyes?

Whenever you see someone with red eyes, you might think, “Has that person smoked cannabis?” Because of this, many people have wondered if edibles have the same effect. After all, if edibles are a way to avoid red eyes, wouldn’t that be great?

If you have any concerns about edibles causing red eyes, you’ve come to the right place. Keep reading to find out what causes red eyes and how to fix them.

What are edibles?

Edibles are cannabis products that you can eat or drink. These products may contain plant material from the cannabis plant or extracted oil such as hemp seed oil, THC oil, and CBD oil.

Most people are familiar with the baked edibles because they’ve been around for quite some time now. However, more recently, with the legalization of marijuana, several other types of edible products are available to choose from.

These include:

  • chocolate
  • soft drinks
  • hard candies
  • gummies
  • lozenges
  • supplements
  • potato chips
  • butter

Symptoms of red eyes

People who use cannabis sometimes develop red eyes. The redness is often a clear sign that someone has been using cannabis, to the point that the condition has become a stereotype associated with marijuana.

The white part of the eye, known as the cornea, changes to a light pink or bright red color. The eye may also look bloodshot, which is caused by inflamed blood vessels.

Besides the obvious red color, there are other eye symptoms. These include:

  • puffy eyelids that may droop down
  • a scratchy or irritated feeling around the eyes
  • inflamed blood vessels around the eye
  • tired eyes
  • dry eyes

These symptoms can look and feel similar to hayfever or allergies. If you’re prone to allergies, it’s worth considering whether your red eyes are linked to allergies or cannabis.

THC makes your eyes red

The good news is that it’s only THC that causes red eyes. If you use CBD, it won’t make your eyes red. This occurs because THC and CBD have slightly different effects on the body.

THC is a vasodilator, which means that it causes your blood vessels to dilate or expand. When the blood vessels dilate, this increases the blood flow to the eyes, making them red.

Thankfully, CBD doesn’t have this same property and it won’t make your eyes red. If you have used CBD and noticed afterwards that your eyes were red, this is most likely caused by an allergy or could be linked to an eye condition.

Smoking cannabis vs edibles

A common misconception is that you can only get red eyes from cannabis when it’s smoked. However, this is not entirely true.

People who smoke cannabis might be more susceptible to experiencing red eyes as a side effect than people who use edibles because the THC in edibles has a slower release.

Regardless of how you use cannabis, you’ll always have a good chance of developing red eyes if the product you’re using contains THC. Therefore, it’s not the smoke or the way you use cannabis that gives you red eyes; THC is the determining factor.

Why does THC make your eyes red?

As mentioned previously, THC is a vasodilator, which makes your eyes red by dilating the blood vessels in your eyes. However, there’s slightly more to this because THC interacts with a bodily system known as the endocannabinoid system.

Throughout your body is a cell signaling system known as the endocannabinoid system. This system is present in many tissues and organs, including the brain, eyes, digestive tract, glands, and immune cells. The main component of this system is receptors that sit on the surface of cells.

These receptors are called cannabinoid receptors, and their role is to receive signals. The signals come from chemical messengers produced by your body that circulate in the blood until they find a cannabinoid receptor.

While your body creates several chemical messengers that can interact with the cannabinoid receptors, chemicals like THC and CBD from outside the body can also interact with them. When THC and CBD bind, they induce effects that other chemicals from within the body can’t.

Additionally, there are two types of cannabinoid receptors: the CB1 receptor and the CB2 receptor. THC predominantly binds to the CB1 receptor and CBD tends to bind to the CB2 receptor.

Because THC and CBD usually bind to different receptors, they have different effects on the body. Eye redness occurs because THC binds to a receptor in the blood vessels of the eyes, which causes the blood vessels to expand. This is why THC gives you red eyes and why CBD doesn’t.

As the blood vessels in the eyes expand, more blood flows into your eyes. With this extra blood flow, the white parts of your eyes become red, the same color as your blood.

Besides increasing the blood flow to your eyes, THC also decreases intraocular pressure. In other words, it reduces the fluid pressure inside your eye.

Some studies have suggested that for people who suffer from glaucoma, a condition where the pressure in the eye is too high, THC offers some relief. So while the red eyes might be an annoying side effect, the reduced pressure might offer a therapeutic benefit.

With chronic use, the side effect of red eyes could subside. Many users on the web claim that their red eyes were worse when they first started using cannabis.

Conversely, some people have never experienced red eyes from cannabis. For some of them, it could just be luck, whereas for others, poor circulation might play a role.

How long do red eyes persist?

Unfortunately, the time frame for how long your eye  redness persists is inconsistent. However, generally, this side effect disappears as you notice the effects of THC subsiding, although some people may notice that their eyes remain red for several hours after that.

How often you use THC is another factor to consider. If you use it often, then your eyes might have adjusted and could overcome the effects of THC more quickly. After long-term use, some people claim they no longer experience red eyes at all.

Lastly, how much you use also influences how long your red eyes persist. If you want to avoid red eyes, you could try reducing your dose. The higher your dose is, the more likely you are to experience red eyes. Higher doses can also make the redness worse.

Do red eyes last longer with edibles?

When using edibles, your red eyes may last longer because edibles have a more sustained effect than smoking cannabis. Some users claim that their red eyes persist for 12 hours after using edible cannabis.

When you smoke cannabis, it can take up to 10 minutes before you notice any effects from THC. Thus, it won’t take long for your body to clear the THC, so your red eyes might disappear more quickly when you smoke cannabis.

With edibles, it can take up to 1 hour before you notice some effect from THC. However, you won’t experience the full effect until 3 hours.

With edible cannabis, the THC has to pass through your digestive tract and liver before it can have an effect on your body. Edibles have a more sustained effect because the THC is being released slowly into the body over a longer period.

The advantage of this slower release is that the intensity of the red eyes might be reduced for some people. However, the disadvantage is that the redness could last longer.

Are red eyes dangerous?

Red eyes caused by cannabis are not dangerous and this side effect will subside as the effects of the THC in your body wear off. However, should the redness persist, it’s worth going to your doctor in case an underlying condition has caused it.

When the eyes are red, they might feel irritated, itchy, swollen, or dry. In that case some treatments are available to alleviate those symptoms until the effects of the THC fade.

As mentioned previously, THC might offer some benefits for your eyes by reducing the pressure of the fluid inside of your eyes. Therefore, for those who have glaucoma, this reduced pressure is a therapeutic benefit.

Treatments for red eyes

One treatment for red eyes is soothing eye drops. Some users on the internet have recommended this treatment because it reduces the redness in their eyes.

Another treatment you could try is splashing some cool water over your eyes. Or, you could wet a face cloth and place it on your eyes for a few minutes. Blood vessels constrict when they’re cold, reducing the amount of blood flowing through them.

If all else fails, you could switch to CBD or reduce the amount of THC you use.

Why haven’t your eyes gone red?

THC affects everyone differently. It can make the eyes red for some people, while for others, it doesn’t. No definitive reason as to why this is the case has been discovered. However, some preexisting health conditions, such as poor circulation or low blood pressure, could be why your eyes don’t go red.

The bottom line

Red eyes are a side effect of cannabis use linked to THC. Whether you smoke cannabis or use edibles, your eyes can still go red. First time users of cannabis are more susceptible to developing red eyes. For chronic users, however, this may not be an issue anymore. If you’re concerned about your red eyes, you could try using soothing eye drops or a cold face cloth.

Kolas University

Sponsored by KOLAS University

Join The Experience

Get Kolas News Weekly

SIGN UP to save money, time, get educated, and find new entertainment!