Your eyes can itch because harmful oxygen molecules side effect damage corneal cells and long-term sleep deprivation leads to corneal cell death. Lack of sleep also damages the tear film, which protects our eyes.
Sleep is essential for all animals in general to maintain their physical and mental health. Unfortunately, however, lack of sleep is a common problem for many people for a variety of reasons. Whether it’s due to busy work habits, late-night gaming, or mothers who are raising young children who can’t get a full night’s sleep.
During sleep deprivation, you may feel that your eyes are becoming very irritated, maybe even itchy. It may not be a pure itch, but a damaged cornea that is giving us trouble. We will first learn about the cornea to understand why lack of sleep makes eyes uncomfortable.
How does the cornea protect the eye?
The cornea is the clear front surface of the eye. It is like a protective eyewear that protects the eyes from infection, dirt and water, and focuses light rays on the retina for our vision. Structurally, the cornea is a protein-containing tissue made up of different types of cells with about 5-7 layers, called the corneal epithelium. This multilayered tissue has different cell types, with one of the main types being the corneal epithelial cells.
Around the surface of the cornea is a smooth, protective layer called the tear gill, which is the first layer that light hits when it hits the cornea. This watery film provides moisture to the eyes, so your eyes won’t dry out, it’s also a source of oxygen for eye cells and other bioprotective molecules.
Our body maintains its vital corneas in a very subtle way. Corneal cells are maintained by a group of stem cells known as corneal epithelial stem cells. These cells can grow and develop into corneal epithelial cells to replace old or dead cells. The cycle of replacing old corneal cells with new cells is called homeostasis.
If you are accidentally hit in the face by a ball and injure your eye, your corneal stem cells will develop into more mature corneal cells to replace the damaged cells. This whole process goes on throughout our lives. But unfortunately, lack of sleep disrupts this balance, causing itchy eyes.
Why do eyes itch?
Most of the day, the cornea is exposed to the sun’s ultraviolet rays and oxygen. The corneal cells break down this oxygen in a specialized manner to release Oxygen Species (ROS). UV rays increase the rate of ROS generation. These are highly reactive and unstable oxygen-containing molecules that damage cellular proteins, lipids, and DNA. This will eventually cause the cells to die.
Many studies have shown that sleep deprivation increases the production of ROS in the body. Interestingly, one study found that sleep-deprived people shed tears with higher ROS levels. This suggests that sleep deprivation also increases ROS levels in the eyes. A study just published in April 2022 done on mice has pushed us closer to answering exactly why our eyes itch. Accordingly, these side effects of harmful oxygen molecules damage corneal cells, while prolonged sleep deprivation leads to corneal cell death.
But that’s also not the full picture. Sleep deprivation disrupts the corneal cell cycle balance, i.e., homeostasis, causing the stem cells of the cornea to divide and grow rapidly, with depletion occurring earlier. In addition, the reactive oxygen species destroy rapidly growing cells and the corneal epithelial stem cells grow faster than normal.
The gene expression of corneal epithelial cells was also disrupted. The study showed that more than 300 genes were not expressed as they should be. Such genetic changes may explain why corneal epithelial stem cells divide so rapidly. Besides, there are reactive oxygen species that damage the tear film – the safety shield for our cornea.
All of these biological effects make our corneas irritated and irritated, leading to us constantly rubbing our eyes. But don’t worry too much, because our body also has a great coping mechanism to take care of itself
How does our body deal with corneal damage?
Sleep deprivation has always been troubling for many people around the world, but not everyone is equally affected. That’s because our bodies have many self-defense molecules that protect the eyes from such damage. In addition to providing moisture and lubrication, it also contains antioxidant molecules such as vitamin C (ascorbic acid) and cysteine that help protect the cornea from ROS damage, or secrete antioxidant enzymes to break it down. ROS molecules.
However, such defenses do not last forever. In the end, sleep deprivation took its toll and the damage done to the body was irreversible. If there is a constant lack of sleep, the tear film damage will get worse. This will weaken the protective ability of the tear film (i.e. its antioxidant capacity). At this point, the oxidative stress burden exceeds what the eye’s antioxidant mechanisms can handle, leading to oxidative damage. The best thing you can do for your body right now is to make sure you get consistent, quality sleep.
Some people don’t get adequate sleep on a regular basis. In that case, seek the help of your ophthalmologist and possibly purchase some eye drops that can ease your discomfort. However, remember that a high-quality sleep is the best thing you can do to maintain good health – for your eyes and every other part of your body.
It is hoped that further studies will focus on developing antioxidant eye drops or drugs that can help eliminate genetic disorders in the eyes, which could help combat eye discomforts in people Sleepless.