The Silent Thief of Sight: How Glaucoma affects Vision 

What is glaucoma?

Glaucoma is a group of diseases that damages the optic nerve-it is the part of the eye responsible for sending visual signals to your brain. According to reports, approximately 2.7 million Americans aged 40 or more have glaucoma and interestingly half of them are not aware that they have it. 

In most of the cases, glaucoma is associated with increased pressure inside the eye, although some people can still develop the condition even with normal pressure. The biggest challenge with glaucoma is that it often progresses slowly and painlessly, making routine eye examinations vital. 

Types of glaucoma

There are two major types of glaucoma:

• Open-angle glaucoma

Most people usually wonder what happens in open-angle glaucoma? Open-angle glaucoma is the most common type that happens gradually. The eye does not drain the fluids the way it should and it leads to clogged drain. This causes pressure build up and starts to damage the optic nerve. It is often painless and there are no vision changes at first. 

• Angle-closure glaucoma

It is also called closed-angle or narrow-angled glaucoma. This happens if the iris is closer to the drainage angle in the eye. The iris can end up blocking the drainage. When the drainage angle gets blocked, eye pressure rises very quickly which is called an acute attack. 

How does glaucoma damage the eye?

Many people have this question, “How does glaucoma damage the eye?” 

Inside the eye, a fluid called aqueous humour is constantly produced and drained. The fluid is drained out from an angle called drainage angle. This process keeps the intraocular pressure, pressure in the eye stable. When this drainage system doesn’t work, the fluid is retained in the eye. But if the drainage doesn’t work properly fluid gets built up. The pressure inside the eye damages the optic nerve. 

The optic nerve is made of more than millions of tiny nerve fibers. As these nerve fibers die, you will develop blind spots in the vision. You may not notice these blind spots until most of your nerve fibers are dead. If all of the nerve fibers die, the person might eventually become blind. 

How does glaucoma affect visual fields?

A visual field refers to everything you see when looking straight ahead, including objects to the side, above and below your direct line of sight. Glaucoma generally creates blind spots in peripheral vision. These blind spots often develop gradually and may be not noticeable at first because the brain compensates by filling in the missing information. Over time, these blind spots become bigger and begin to merge. 

Patients might experience:

• Difficulty observing things at the side
• Trouble navigating crowded places
• Increased risk of falls or accidents
• Challenges while driving
• Awareness of the surroundings

Regular visual field testing helps optometrists detect these changes before people become aware of it. 

Impact of glaucoma on your eyesight

One of the questions that has been hyped is, “ How does glaucoma affect your eyesight?”, “How does glaucoma cause peripheral vision loss?” The impact that glaucoma has on eyesight is:

• Loss of peripheral vision

You might begin to bump into things or have trouble seeing objects outside your peripheral vision.

• Reduced night vision 

It can be difficult for people to see in low-light conditions such as at night or dimly-lit rooms. 

• Tunnel vision

Tunnel vision is basically the loss of peripheral vision in both the eyes. As the condition advances, the patient can only see what is exactly in front of him.

• Halos

The occurrence of rainbow-coloured circles or bright lights that appear around lights especially at night is halos. 

How long does it take for glaucoma to cause vision loss?

One of the common questions patients ask is, “ How long does it take for glaucoma to cause vision loss?” Unfortunately there is no single answer. The rate of progression varies depending on age, type of glaucoma, eye pressure falls, overall health, genetics and how early the treatment begins. 

For some individuals, glaucoma may progress very slowly over many years. Others may experience faster optic nerve damage if the condition remains untreated. The good news is that early diagnosis and appropriate treatment can significantly slow disease progression and help preserve vision for decades.

How does Glaucoma make you build?

People often wonder, how does glaucoma make you blind if it only starts with mild vision changes. The answer lies in ongoing optic nerve damage. As glaucoma progresses, more nerve fibers are destroyed. Peripheral vision loss becomes more extensive, eventually affecting central vision as well. I advance stages people might experience:

• Severe tunnel vision
• Difficulty recognising faces
• Trouble reading
• Loss of independence and mobility
• Complete blindness in extreme untreated cases

Vision lost due to glaucoma generally cannot be restored. This is why prevention and early intervention are so important. 

How is glaucoma diagnosed?

The only way to diagnose glaucoma is with a complete eye test. During a glaucoma eye test, your optometrist:

• Measures eye pressure
• Inspect your eye’s drainage angle
• Examines your optic nerve for eye damage
• Tests your peripheral vision
• Measures the thickness of the cornea

These may include:

• Eye pressure measurement

Tonometry is a quick, painless test that measures the intraocular pressure inside your eye. The physician usually numbs the eyes with drops and uses a tiny instrument to lightly touch the surface. 

• Visual field testing

This is also known as perimetry which is a test that maps the whole field of vision. You will be asked to stare straight ahead and then click a button when you see a light in your peripheral vision to detect blind spots. 

• Optical Coherence Tomography

It is a non-invasive imaging test that is similar to sonography but the only difference is it uses light waves. It takes high resolution 3D images of the retina and optic nerve fibers to detect the early signs of glaucoma. 

• Gonioscopy

A diagnostic test where the optometrist puts a contact lens on your eye and examines the drainage angle where the iris and cornea meet. 

Final Thoughts

Glaucoma damages the optic nerve in the eye and is one of the leading causes of blindness. Understanding how glaucoma affects your eyesight, how glaucoma affects visual fields, and how glaucoma causes peripheral vision loss can help individuals recognize the importance of early detection.

Whether you are wondering how long it takes for glaucoma to cause vision loss, how glaucoma damages the eye, or how glaucoma makes you blind, the key message remains the same: early diagnosis matters. Regular eye examinations and prompt treatment can significantly reduce the risk of permanent vision loss and help preserve your sight for years to come.