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Causes of Sudden Blindness: Are You at Risk? And is it Irreversible?

Written by Stephanie Nera, RPh, PharmD · Pharmacology

Updated May 19, 2021

Causes of Sudden Blindness: Are You at Risk? And is it Irreversible?

Unfortunately, not everyone has perfect vision. Many people of all ages rely on corrective glasses and contact lenses to see clearly. Vision deterioration is gradual, especially as we age. However, sudden loss of vision or ability to see colors is not a good sign. Here are some causes of sudden blindness that you should be aware of.

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Causes of Sudden Blindness

Exposure to chemicals

Strong acids and bases are extremely damaging to skin and other tissues. Caustic and corrosive chemicals like bleach, muriatic acid, and even acetic acid (a.k.a. vinegar) are common household items that can be dangerous. Many people wear gloves while using these chemicals but fail to protect their eyes. Chemical exposure includes direct contact and indirect exposure via fumes. Aside from vision loss, chemical exposures can cause redness, irritation, watering, and pain.

Splashes and spills can happen while cleaning or cooking. To prevent chemical burns and permanent eye damage, immediately rinse your eyes with clean, running water. Continue to do the flushing or eyewash for 5 to 20 minutes, depending on the chemical exposure. It is advisable to seek medical attention or get checked by your doctor even after doing an emergency eyewash.

causes of sudden blindness

2. Physical injury or accidents

Direct injury to the eye or head can cause sudden loss of vision, either temporarily or permanently. Facial injuries due to sports or car accidents can injure structures around the eye or the actual eyes. Paralysis of the eyelid will cause drooping or involuntary closure, known as ptosis.

In severe cases of physical head trauma, the retina may become torn or detached. The retina is the thin layer of tissue that lines the inner eyeball and is responsible for detecting light. Signs of retinal detachment include seeing floaters or dark spots in your vision, flashes of light, or large shadows in your field of vision, sometimes described like a curtain falling down.

Punctures, penetration, and retinal detachment are medical emergencies that should be treated at a hospital. Ptosis may be temporary, but usually indicates an underlying neurological or mechanical condition.

3. Diabetic retinopathy

Similarly, long-standing and poorly managed diabetes can damage the retina. High blood sugar can affect the small blood vessels that supply the eye and retina. When these vessels are damaged, the retina cells receive less oxygen and can’t relay signals to the brain. This results in blindness or vision loss.

Damaged blood vessels are replaced by new but fragile capillaries. As blood leaks around the retina and scar tissue is formed, a proliferative membrane, which causes traction and subsequent retinal tears, may form. In addition, blood may fill the entire inner eyeball. The results are blurry vision, floaters, and eventually blindness.

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4. Blood clot

Another one of the causes of sudden blindness is blood clots. While we often associate atherosclerosis and clots with the heart, these can affect our eyes and vision as well. Unlike other causes of vision loss like chemical or physical trauma, blocked vessels may not cause pain. Typically, a clot will affect one eye at first, but vision loss can occur in both eyes if there are separate clots.

As described previously in diabetic retinopathy, a blocked or damaged vessel can prevent oxygenation of eye tissue. The most common blood vessels affected by clots are the central retinal artery and vein. Additionally, the arteries that supply the optic nerve are commonly blocked, resulting in blindness.

5. Stroke

Lastly, one of the less common but more serious causes of vision loss is stroke. A stroke occurs when a clot reaches the brain and blocks blood flow. These areas of the brain receive less blood, oxygen, and nutrients. The brain is especially sensitive to oxygen shortages and ischemic areas quickly die.

The symptoms of a stroke largely depend on the area of the clot. The occipital lobe is the back area of the brain, responsible for receiving signals from the eyes. This area controls how we see things and a stroke in this area can cause sudden blindness. Aside from stroke, trauma, high blood pressure, severe dehydration, and viral infections may also affect the occipital lobe function.

Key Takeaways

In summary, there are several causes of vision loss that are common and uncommon. Eyes are extremely sophisticated yet delicate organs that let us see the world around us. While accidents happen, other causes can be largely prevented. If you experience any sudden loss of vision, contact your doctor as soon as possible or seek emergency medical care.

Learn more about Vision Problems here. 


Hello Health Group does not provide medical advice, diagnosis or treatment.

Written by

Stephanie Nera, RPh, PharmD


Updated May 19, 2021

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