What Is Glaucoma? Early Signs and Eye Tests

Last updated: 25/06/2026

Many people ask: What Is Glaucoma? Glaucoma, sometimes called blue water disease, is a disease that affects the optic nerve in the eye. It is often linked to high eye pressure or a problem with fluid drainage inside the eye.

The risk of glaucoma in the eye is that it may develop gradually without clear symptoms at first. Therefore, understanding the early signs, diagnosis methods, and treatment options helps patients know when an eye exam is necessary to protect vision. This guide explains What Is Glaucoma in a simple way for patients who want to understand the condition before seeking medical evaluation.

 

If you have a family history of glaucoma, notice a change in vision, or want to check your eye pressure and optic nerve health, you can contact the Magrabi team via WhatsApp to learn the most appropriate medical step for examination and follow-up.

What Is Glaucoma?

Glaucoma is a group of eye disorders that affect the optic nerve, which is the nerve that carries visual signals from the eye to the brain. When this nerve is affected, vision may begin to change gradually, especially at the edges or sides.

The Saudi Ministry of Health explains that glaucoma, or blue water disease, may lead to gradual damage to the optic nerve. It may be linked to increased eye pressure when the fluid inside the eye is not drained properly.

Therefore, when asking What Is Glaucoma, the answer is not limited to high eye pressure only. Glaucoma in the eye may occur with high pressure, and in some cases it may appear even when eye pressure is not clearly elevated. For this reason, diagnosis requires a comprehensive medical examination.

What Are the Causes of Glaucoma?

The causes of glaucoma vary from one case to another, but the common cause is related to fluid inside the eye not draining in the normal way. When this fluid builds up, eye pressure may increase, which can place pressure on the optic nerve over time. Factors that may increase the risk include:

• High eye pressure.
• A family history of glaucoma disease.
• Older age, especially after the forties or fifties.
• Diabetes or high blood pressure.
• A previous eye injury.
• Some types of previous eye surgery.
• Long-term use of corticosteroid medications without follow-up.
• Severe nearsightedness or farsightedness.
• Problems in the cornea or optic nerve.
• Some congenital conditions in children.

For this reason, the cause of glaucoma cannot be identified from symptoms alone. The doctor needs to examine eye pressure, the optic nerve, and the visual field to determine the most likely cause and follow-up plan.

What Are the Types of Glaucoma?

To understand What Is Glaucoma correctly, it is important to know that it is not one identical condition in all patients. There is more than one type of glaucoma in the eye, and each type differs in how it appears, how quickly it progresses, and how it affects eye pressure and the optic nerve. The main types include:

• Open-angle glaucoma: This is one of the common types. It often develops slowly and does not cause pain or clear symptoms at first.
• Angle-closure glaucoma: This may appear suddenly with severe pain, redness, and blurred vision. It requires urgent evaluation.
• Normal-tension glaucoma: In this type, the optic nerve is affected even though eye pressure is not clearly high.
• Secondary glaucoma: This may occur because of an injury, inflammation, previous surgery, or the use of some medications.
• Congenital or childhood glaucoma: This appears in newborns or children because of a problem with fluid drainage in the eye.

The Qatar Ministry of Public Health notes the importance of early vision screening and not ignoring changes in vision. This is important when discussing the types of glaucoma, because identifying the type helps the doctor choose the appropriate follow-up or treatment.

What Are the Symptoms of Glaucoma?

Glaucoma symptoms may not be clear at first, especially in open-angle glaucoma. For this reason, some patients discover the condition during a routine eye exam, not because of a direct complaint. As the condition progresses, it may gradually affect side vision or the visual field. Possible glaucoma symptoms may include:

• Gradual weakness in side vision.
• Unclear areas in the visual field.
• Blurred or cloudy vision.
• Seeing halos around lights.
• Difficulty noticing objects from the sides.
• Headache or eye strain in some cases.
• Severe pain and redness when eye pressure rises suddenly.
• Nausea or vomiting with eye pain in acute cases.

Because glaucoma symptoms may not be clear at first, understanding how a glaucoma patient sees helps you notice subtle changes in side vision and the visual field before they become more disruptive in daily life.

The NHS explains that glaucoma often causes no symptoms at first and may be detected during a routine eye exam. However, some sudden types may cause severe pain, redness, halos around lights, and blurred vision.

How Is Glaucoma in the Eye Diagnosed?

Diagnosing glaucoma in the eye does not depend on measuring eye pressure alone. Eye pressure may be normal in some cases, while changes appear in the optic nerve or visual field. A glaucoma examination may include:

• Measuring eye pressure.
• Examining the optic nerve.
• Testing the visual field.
• Imaging the optic nerve or retinal layers when needed.
• Examining the drainage angle inside the eye.
• Assessing corneal thickness.
• Reviewing family and medical history.

Magrabi ophthalmologists explain that early diagnosis helps identify the type of glaucoma in the eye and choose the appropriate follow-up or treatment for each case. This also helps patients understand What Is Glaucoma beyond eye pressure alone.

What Are the Treatment Options for Glaucoma Disease?

Treatment for glaucoma disease depends on the type of glaucoma, eye pressure, the condition of the optic nerve, and visual field test results. Therefore, there is no single plan that suits all patients. Treatment options may include:

• Eye drops that help lower eye pressure.
• Additional medications in selected cases decided by the doctor.
• Laser treatment to improve fluid drainage inside the eye or reduce pressure.
• Glaucoma surgery if eye drops or laser treatment are not enough.
• Regular follow-up to check eye pressure and the optic nerve.
• Treating the underlying cause if glaucoma is secondary to inflammation, injury, or a specific medication.

When Should You Visit an Ophthalmologist?

Doctors at Magrabi Hospitals recommend seeing an ophthalmologist when there are repeated symptoms or risk factors that may be linked to glaucoma disease. It is not recommended to wait for clear vision loss, because some cases begin without noticeable symptoms. An eye exam is needed when there is:

• A family history of glaucoma.
• Previous high eye pressure.
• Recurrent blurred vision.
• Weak side vision.
• Seeing halos around lights.
• Repeated eye pain or redness.
• A previous eye injury.
• Long-term use of some corticosteroid medications.
• Diabetes or high blood pressure that requires regular follow-up.

 

To understand What Is Glaucoma more clearly and how eye pressure and the optic nerve are checked, visit Magrabi’s glaucoma service page for diagnosis, follow-up, and treatment options 

How Can You Tell the Difference Between Glaucoma and Cataract?

Some patients may confuse glaucoma and cataract because both can affect vision. However, the difference is important. Glaucoma usually affects the optic nerve, while cataract affects the lens of the eye and causes gradual clouding of vision.

Therefore, the cause cannot be identified based on the description of vision alone. The doctor needs to examine the eye to determine whether the problem is related to glaucoma in the eye, cataract, or another condition. You can also read more about cataract treatment in the eye to understand the difference between lens problems and optic nerve problems.

 

To get a more accurate medical evaluation of eye pressure and optic nerve health, you can book an appointment at Magrabi Health through a phone call or the booking form.  to discuss your condition with an ophthalmologist.

Conclusion

Understanding What Is Glaucoma helps patients deal with the condition with greater awareness, because it may gradually affect the optic nerve without clear symptoms at first. For this reason, checking eye pressure and the optic nerve remains an essential step for detecting glaucoma in the eye early and choosing the appropriate treatment before vision is affected more significantly. With regular follow-up and commitment to the doctor’s instructions, eye health can be supported and the risk of long-term vision deterioration may be reduced.

References

• Saudi Ministry of Health – Glaucoma
• National Eye Institute – Glaucoma
• Mayo Clinic – Glaucoma Symptoms and Causes
• NHS – Glaucoma
• Qatar Ministry of Public Health – Vision Screening in the Early Years
• Egyptian Ministry of Health and Population – Official Website
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Medically reviewed by Dr. Hassan Adel.

Medical Disclaimer: The information in this article is for health education purposes only and does not replace a visit to a doctor or consultation with a qualified specialist. Magrabi doctors recommend seeing a doctor to evaluate the condition accurately and determine the appropriate treatment.