Dry Eye Vs Glaucoma: What’s the Difference?

What is dry eye exactly? What about glaucoma? And why are the two conditions sometimes confused?

Read on to learn more about dry eye vs glaucoma, the links between them, and how to preserve your vision.

What Is Dry Eye?

Dry eye disease is a common and often underdiagnosed condition that causes a wide range of symptoms in one or both eyes. It’s also known as dry eye syndrome.

Dry Eye Symptoms

Common dry eye symptoms include tired, gritty, or scratchy eyes, soreness or burning in the eye, redness, blurry vision, light sensitivity, and tearing.

When you have dry eyes, you may also feel that you have something in the eye that you can’t get rid of no matter how much you blink.

Dry eye symptoms may come and go and vary from one person to another. They can also be subtle enough for you to ignore them at first.

If your eyes just don’t feel right and bother you while reading or looking at a screen, it may be dry eyes.

Dry Eye Causes

Dry eye occurs when the tear glands found above each eye don’t make enough tears, or when there is an imbalance in the quality of the tears.

The tear film consists of oily, watery, and mucin layers. These layers need to be in balance for the tear film to lubricate the surface of the eye and protect it from dust particles and bacteria. You can read more about dry eyes here.

Prolonged computer or screen use may cause dry eyes. Screen time changes your natural blink rate and may disrupt your tear film.

Other common causes include working in a low humidity or air-conditioned environment, constant wind exposure, or suffering from eye infections, eyelid inflammation, or certain diseases such as rheumatoid arthritis.

Having had eye surgery or taking antidepressants, antihistamines, and other medication also increases the risk for dry eye. Nutritional deficiencies may also interfere with tear production.

Dry Eye Incidence

Older people are more likely to have dry eyes, but the condition can occur at any age. In recent decades, the incidence of dry eyes among younger people has been increasing. Widespread screen use is likely a contributing factor.

A 2017 global report estimated that 20 to 50% of people have dry eyes. According to other sources, up to 6 million Canadians and as many as 49 million Americans have dry eyes.

What Is Glaucoma of the Eye?

Glaucoma is a leading cause of irreversible blindness worldwide. It refers to a group of eye diseases that damage the optic nerve that connects the retina at the back of the eye to the brain.

To fully understand what is glaucoma, it’s important to know that there are different types of glaucoma. These include open-angle glaucoma, normal-tension glaucoma, narrow-angle glaucoma, and congenital glaucoma.

Glaucoma can also be caused by other medical conditions, such as high blood pressure or diabetes (neovascular glaucoma), uveitis (uveitic glaucoma), and cataracts.

Glaucoma Symptoms

In its early stages, glaucoma may not cause any noticeable symptoms. But as it progresses, it can lead to the gradual and irreversible loss of peripheral (side) vision and blind spots.

Symptoms vary depending on the type of glaucoma, with some causing high eye pressure, intense pain, and seeing rainbow-colored rings around lights.

Glaucoma Causes

Glaucoma is often caused by a build-up of aqueous humor, a fluid that fills the inside of the eye. When there’s too much of this fluid, or when it doesn’t drain properly, eye pressure increases.

Over time, high eye pressure damages the optic nerve. High intraocular pressure can also be the result of a bulging iris.

Some people have glaucoma without high eye pressure. Known as normal-tension glaucoma, the cause of this condition is not known. But the optic nerve of those affected appears to be more susceptible to damage.

Glaucoma Incidence

Glaucoma can occur at any age, but it’s most common in older adults. A recent study estimated that 76 million people suffered from glaucoma in 2020, with that number set to increase to over 111 million by 2040.

Glaucoma affects over 400,000 Canadians and about 3 million Americans. Having a history of glaucoma in the family may predispose you to the condition.

Differences Between Glaucoma and Dry Eye

Glaucoma and dry eye often occur together, but they are different conditions. Advanced glaucoma causes vision loss, while dry eye causes mostly eye discomfort and leads to eye damage only if it’s not treated.

According to the Glaucoma Research Foundation, 40 to 50% of glaucoma patients have dry eyes. What’s more, 60% of people treated for open-angle glaucoma or hypertension in the eye have dry eye symptoms.

Eye drops prescribed to glaucoma patients often contain the preservative benzalkonium chloride, which can cause dry eyes and other side effects. But even before glaucoma treatment begins, patients with glaucoma are more predisposed to dry eye.

Glaucoma and dry eyes are often undiagnosed. According to estimates, half of the people with glaucoma don’t know they have the condition.

While there is no cure for glaucoma, prompt treatment helps preserve vision. Meanwhile, untreated chronic dry eye can cause abrasion and ulcers on the cornea and lead to vision loss that makes everyday activities such as reading or driving difficult.

Important: If you have dry eye, glaucoma could also be affecting one of your eyes, especially if you are over 60. Getting a comprehensive eye exam is a good idea since early glaucoma symptoms can be so subtle they are difficult to notice.

Dry Eye vs Glaucoma Summary

• Glaucoma and dry eyes are chronic eye conditions affecting mostly the elderly, but which can appear at any age. Having one condition doesn't exclude the other—some people get both.
• Glaucoma treatments through eye drops may cause dry eyes.
• Dry eye may cause more uncomfortable symptoms than glaucoma at first. But since the latter damages eyesight, most doctors will prioritize its treatment.
• Not addressing dry eye symptoms if you have glaucoma can lower your quality of life. It can also demotivate you from following up on your glaucoma treatment for preserving your eyesight.
• If you have been diagnosed with glaucoma, whether or not you are experiencing symptoms, it’s important to get checked for dry eye.
• Dry eye symptoms can also be subtle enough for you to ignore them at first, especially if you never had eye health problems before.
• A dry eye diagnosis will enable you to get the condition treated and encourage you to make dietary and lifestyle choices that can help you better manage it.

Do You Have Dry Eyes?

Glaucoma screening requires a visit to an eye doctor. If you have a family history of glaucoma, are an older citizen, or are simply concerned about your eye health, getting screened for glaucoma can be prudent.

Catching it before the symptoms begin affecting your everyday life and treating it accordingly can help you preserve your vision.

Dry eye is more common than glaucoma and can occur at any age. Diagnosing dry eye is also easier. Our online dry eye test can help you discover whether you may have the condition.

Give your eyes the attention they deserve and preserve your vision for years to come.