You might feel like you have sand in your eyes, or they might burn or itch. You might be sensitive to light, have blurry vision, or, in some cases, your eyes might water. And you may have a tough time wearing contact lenses.
Your Eyes Need Moisture
This helps them work the way they’re supposed to and keeps them comfortable. Your body normally makes moisture for your eyes, but when you can’t — or it’s not good quality — that can make your eyes hurt and affect your eyesight.
What Your Tears Do
They soothe the surface of your eyes and protect them from things like debris and infection. Each time you blink, they go over your eyes, then drain into the inner corners of your eyelids to the back of your nose. If you don’t make enough good-quality tears, your eyes can be dry and irritated.
Dry Eye Syndrome
The second most common kind of dry eye happens because your body doesn’t make enough tears. This is called dry eye syndrome, or keratoconjunctivitis sicca (KCS). Many things can cause it. Depending on what that is, it can go away on its own or last a long time.
Possible Cause: Age
The glands that make tears don’t work as well as you age, so you don’t make as many. Also, your eyelids begin to sag, and that can break the seal against your eyeball that helps keep in moisture.
Possible Cause: Certain Illnesses
Autoimmune diseases — when your immune system attacks parts of your body — can affect your body’s ability to make tears and cause dry eyes. Examples include lupus and rheumatoid arthritis, as well as Sjogren’s syndrome, which attacks saliva and tear glands.
Evaporative Dry Eye
If your tears don’t have enough oil in them, they can evaporate (get absorbed into the air) before your eyes get enough moisture–the most common cause of dry eyes. This often happens when the glands that give your tears their oily texture are blocked. Also called Meibomian gland dysfunction, it’s treated with warm washcloths and lid scrubs that clear away the dead skin, oil, and bacteria that can build up and plug the glands.
Tear Duct Infection
Also called dacryocystitis, this happens when a tear duct — the small tube that runs down the length of your nose and connects to your eyelid — gets blocked and bacteria get in the area. It’s most common in infants, but it can happen at any age. Symptoms include pain, redness, swelling, too many tears, discharge from your eye, and fever. Antibiotics are the most common treatment, but some people need minor surgery to clear it up.
Your Retina Is Damaged
The retina (which includes your macula) is the back part of your eye where light gets focused, like a movie screen. If something happens to that surface, like swelling or tearing, the picture can be distorted or lost. A family history of retinal disease, poor diet, smoking, previous eye injuries or disease, and health issues such as high blood pressure, high cholesterol, and diabetes can raise the odds of problems like macular edema and a detached retina.
It’s Something in Your Brain
A concussion or brain injury could disrupt how information from your eyes gets processed. Depending where and how big it is, a brain tumor may affect your sight. Double vision can be one of many symptoms of brain swelling or of the membrane that surrounds it (encephalitis or meningitis), often because of infection. While it’s not a symptom people usually think of, sudden blurry vision can be a sign of a stroke or another serious problem
Credit: webmd
