Comparison Between Glaucoma And Normal Eye

When it comes to the health of our eyes, we often take for granted that everything is just fine until something goes wrong.

And even then, many people only seek medical attention when they can no longer deny there is a problem.

One such eye condition that tends to go undetected or ignored for too long is glaucoma. 

Glaucoma is a condition that can lead to blindness if not treated in time.

But, in what ways do glaucoma eyes differ from “normal” eyes, you might ask?

And what should we be on the lookout for when it comes to this particular condition?

Also, how does having a higher eye pressure affect your vision and what can you do to maintain healthy eye pressure?

Find out in this blog post!

What is Meant by Glaucoma?

Glaucoma is an eye condition or disease, which causes damage to your eye’s visual field and can lead to blindness if it isn’t caught on time by a doctor.

It occurs when the fluid inside your eye overfills, causing pressure to build up due to decreased drainage outflow of fluids through the trabecular meshwork.

Essentially, this intraocular pressure can damage the optic nerve, which is responsible for carrying images from your eye to your brain.

There are usually little to no warning signs of glaucoma until significant vision loss has occurred.

That’s why it’s sometimes called the “silent thief of sight” because it occurs over time rather than suddenly.

However, when glaucoma advances and optic nerve damage occurs, the patient may begin to experience a gradual loss of vision, which is the disease’s first noticeable sign.

Fortunately, early diagnosis and treatment of glaucoma can help slow the progression of vision loss, minimize damage to your eye’s optic nerve, and reduce future risk for complete blindness.

Causes of Glaucoma 

One main characteristic of glaucoma is abnormally high intraocular pressure (IOP).

Although elevated IOP isn’t always present in all types of glaucoma, it is the main cause of the disease.

When the aqueous humor cannot drain a sufficient amount, a build-up of intraocular pressure (IOP) inside the eye occurs.

The aqueous humor is a watery substance that fills the anterior chamber of your eyes. 

It helps maintain the shape of your eye and nourishes its tissues.

The fluid drains out through a mesh of tiny drainage holes known as a trabecular meshwork of your eyes.

This is a group of tiny, sponge-like structures in the eye that keep the IOP from building up behind your eye’s lens and iris.

If an obstruction occurs in this fluid flow system, the fluid then accumulates and exerts pressure inside your eye, and damage to your optic nerve occurs.

As damage to your optic nerve progresses, your vision begins to decrease and you may eventually go blind.

The causes of elevated intraocular pressure (IOP) inside your are not entirely understood, but the following may play a role:

  •  Injury to the eye
  • Inflammation or infection of the eye
  • Blockage of the drainage system in your eye
  • Certain medications, such as corticosteroids or glaucoma eye drops that contain prostaglandin
  • Excessive production of aqueous humor

Factors that Influence Glaucoma 

Several things can contribute to the development of glaucoma.

Here are some of the key things that can increase your risk of the disease:

  • Age: Glaucoma is more common in older adults. The majority of people who have glaucoma are over 60 years old
  • Race: African Americans, Asian Americans, and Hispanic/Latino individuals are at a higher risk of developing glaucoma
  • Family history: If someone in your family has been diagnosed with glaucoma, it means that you could be more likely to get the disease as well. Glaucoma often runs in families
  • Disease or condition: Having certain diseases or conditions, such as diabetic retinopathy, can increase your chances of getting glaucoma
  • Eye injury: If you have had an eye injury that resulted in a scar on the iris, it may make you more prone to developing glaucoma.
  • Eye surgery: Some types of eye surgery, such as LASIK could increase your chances of glaucoma
  • Medications: Some medications can make you more likely to get glaucoma, including steroids and antihistamines
  • High eye pressure: One of the main risk factors for glaucoma is elevated eye pressure. If your eye pressure is consistently above normal levels, you are at a higher risk of developing the disease

Comparison Between Glaucoma Eye Pressure and Normal Eye Pressure 

Some people may be wondering if there is any difference between glaucoma eyes and normal eyes. 

The answer to this question is that yes, there are some differences.

For example, individuals with glaucoma are more likely to have a higher intraocular pressure (IOP) than those without the condition. 

While there is no foolproof way to prevent glaucoma from developing, knowing these risk factors can help people take steps to reduce their chances of developing the disease.

Normal Eye Pressure 

The Glaucoma Research Foundation suggests that a normal intraocular (inside the eye) pressure level should be about 12-22 mm Hg.

The mm Hg measurement is the normal unit of measurement for eye pressure in millimeters of mercury.

When your IOP registers higher than 22 mm Hg, it does not necessarily mean you have glaucoma, but it is a significant risk factor and should be monitored.

Sometimes, your intraocular pressure (IOP) might be higher than normal, yet you don’t have signs or symptoms of glaucoma. This is referred to as ocular hypertension.

This condition also needs monitoring because untreated, increased eye pressure can cause damage to the optic nerve.

Also, individuals with ocular hypertension are five times more likely to develop glaucoma than those with normal eye pressure.

That’s why it’s important to have a comprehensive eye exam at least every two years, whether or not you think you have any problems with your vision.

Remember, the risk of vision loss increases with each passing year if left untreated or uncontrolled.

Thus early detection can help catch elevated eye pressure before it does too much damage.

High Eye Pressure 

When your IOP is normal, it should be below 22 mm Hg and may fluctuate between 12-22 mm Hg throughout the day or even within a specific timeframe.

So, what does this mean?

If this number is consistently higher than 22mmHg after several tests, then you’re diagnosed with high eye pressure, thus a glaucoma suspect.

A glaucoma suspect can also be someone who has shown potential glaucoma risk factors, such as glaucomatous optic nerve changes or a family history of glaucoma.

It is also important to keep in mind that high eye pressure is a major risk factor for glaucoma and can lead to optic nerve damage if left untreated.

And once the optic nerve damage has been done, there is no reversing.

At first, the damage may not only affect your peripheral (side) vision but can slowly cause glaucomatous changes that may lead to vision loss.

These vision changes may be so gradual that you don’t notice them until later stages of the disease when central vision has also been decreased and then lost.

This is the most typical way visual impairment from glaucoma blindness manifests itself.

If you’ve been diagnosed with high eye pressure, we strongly advise seeing an eye doctor immediately. 

This way, they can develop a glaucoma treatment plan that can help bring your IOP down to a normal level and slow down the progression of glaucoma.

Additionally, a glaucoma suspect should have their eye pressure checked regularly to prevent further vision loss while still in a treatable stage of glaucoma. 

Symptoms of Glaucoma 

Most people who have glaucoma don’t experience any symptoms until the disease has progressed to a more advanced stage, damaging their central vision.

However, some people may notice early signs and symptoms of glaucoma, such as painless, gradual loss of peripheral (side) vision in the field of vision.

This type of vision loss can spread to central vision over time and is often associated with the disease’s severity.

As the disease progresses, there may be other noticeable symptoms, but they might differ depending on the type of glaucoma and its severity.

Acute Angle-Closure Glaucoma

The signs and symptoms of acute angle-closure glaucoma (AACG) appear suddenly.

Patients may experience:

  • Eye pain
  • Nausea and vomiting
  • Halos around objects
  • Seeing a yellow spot or having a blurred vision that remains even after the other symptoms have passed
  • Severe headache
  • Eye redness

Open-Angle Glaucoma 

When open-angle glaucoma symptoms appear, they can include:

    • Loss of peripheral vision
    • Reduced vision
    • Swelling or bulging of the cornea
  • Nausea 
  • Eye redness, especially the white part of the eye

Note that some of these symptoms are also common symptoms experienced by people without glaucoma.

Also, the absence of symptoms does not mean you do not have glaucoma. Always see an eye doctor for a diagnosis.

Types of Glaucoma & Their Causes

Different types of glaucoma exist, each caused by a different mechanism.

Let’s take a look.

Acute Angle-Closure Glaucoma

Acute-angle closure typically occurs when the iris (the colored part of the eye) bulges forward and becomes too close to the eye’s drainage angle. 

This blocks fluid from draining and causes an increase in pressure within the eye, leading to a sudden onset of symptoms.

This type of glaucoma is a medical emergency, as it can cause permanent vision loss within days or hours if left untreated.

Fortunately, acute angle-closure glaucoma is rare. 

Most cases occur in people with narrow drainage angles who have not been previously diagnosed with glaucoma. 

These individuals may experience a sudden onset of blurred vision, halos around lights, eye pain, and nausea.

Open-Angle Glaucoma 

According to the National Eye Institute (NEI), the most common form of glaucoma is primary open-angle glaucoma (POAG). 

POAG occurs when the drainage canals within the eye are partially blocked, causing intraocular pressure to rise gradually. 

This pressure often damages the optic nerve, leading to gradual vision loss.

It usually develops slowly over time without any initial symptoms or noticeable vision changes. 

This is in contrast to acute closed-angle glaucoma, which typically develops suddenly and causes a great deal of pain.

Normal-Tension Glaucoma 

Typically, normal-tension glaucoma is a type of glaucoma that occurs even when the pressure inside the eye is normal or too low to cause vision loss. 

The cause is not fully understood, but one possibility is that your optic nerve is susceptible or has reduced blood flow.

This type of glaucoma can be difficult to diagnose because the symptoms are often milder than those caused by other types of glaucoma.

That’s why it is classified as a “slow, less aggressive form” of a typical primary open-angle glaucoma.

Pigmentary Glaucoma 

It can seem strange that pigmentary glaucoma is also a result of elevated eye pressure. However the results are due to high blood pressure in the eyes. 

Pigmentary glaucoma is characterized by pigment deposits in the trabecular meshwork and aqueous humor outflow pathway of the eye.

This leads to a reduction in aqueous flow, which can lead to increased resistance and elevated intraocular pressure (IOP). 

Activities such as jogging can increase the odds of the granular pigments becoming loose.

In turn, this can cause the pigment to flow into and obstruct trabecular meshwork, leading to a rise in IOP.

Congenital Glaucoma

Did you know that congenital glaucoma can occur at birth or in the first years of life?

This type of glaucoma can be caused by an abnormal drainage system in the eye or a blocked angle between the cornea and iris.

This, too, may cause the fluid pressure inside the eye to increase, leading to optic nerve damage.

Babies born with congenital glaucoma often have cloudy eyes and are sensitive to light. 

When Should Someone See a Doctor 

Most people wonder when they should see a doctor about their eye pressure.  

Some even think that everything must be okay because they don’t have any symptoms.

However, it’s important to get your eyes checked regularly even if you feel fine because many times, there are no symptoms until the damage has been done. 

In fact, most people won’t have any symptoms until it’s too late. 

A lot of times, the only way to tell if someone has high eye pressure is with a test called tonometry.

Also, if you notice any changes in your vision or eye pain, you should see your doctor right away.

The Bottom Line

While the pressure inside a glaucoma eye is higher than in a normal eye, it’s important to remember that not everyone with high eye pressure will develop glaucoma in their lifetime. There are many other factors that contribute to the development of this disease, such as your family history and race. If you’re concerned about your risk of developing glaucoma, talk to your eye doctor and ask for a comprehensive dilated exam. This way, if you have high pressure in your eyes, they can catch it early and take action to lower the risk.



Frequently Asked Questions 

What does vision look like with glaucoma?

One of the most common symptoms of glaucoma is decreased vision. This can be subtle at first, and many people don’t realize they have a problem until it’s too late. In advanced cases, patients may experience total blindness in one or both eyes.

If you’re experiencing any changes in your vision, even if you don’t think they’re that severe, it’s important to go in for an eye exam. If you do have glaucoma, catching the signs early means you can quickly take action and even stop further vision loss.

What are the warning signs of glaucoma?

Some of the warning signs of glaucoma include a sudden increase in eye pressure, blurred vision, halos around lights, red eyes, and pain in or around the eyes. If you experience any of these symptoms, it’s important to see an ophthalmologist as soon as possible. Left untreated, glaucoma can lead to permanent eyesight loss.

Can you see glaucoma in the eye?

Yes! But it is not completely the same as normal eyes. The eye doctor will check for glaucoma with an ophthalmoscope, which helps to see the inside of the eyeball. A magnified view allows you to have a closer look at your retina and optic nerve head in order to find out if there are any changes that could indicate glaucoma.

Can I live a normal life with glaucoma? 

Glaucoma is a painless disease that can lead to blindness. It affects the eyes, but it doesn’t directly affect your quality of life until there are significant changes in your vision and other eye structures such as your optic nerve or retina. So, if you catch it in time, perhaps with regular eye exams for glaucoma, or are diagnosed early, you can live a normal life with glaucoma.


Eric Gutenberg
Author: Eric Gutenberg