Six Causes Of Sudden Vision Loss

Published on 06/27/2022
six causes of sudden vision loss

Sudden vision loss or blurred vision in one or both eyes is scary. Contact your optometrist immediately if this happens to you or someone you love. Your urgent care provider of choice should handle after-hours incidents.

Sudden vision loss is defined as vision loss that gets notably worse in minutes or within a few days or so. In almost all cases, what seems like sudden vision loss at the moment is not as sudden as patients report. When we begin to question patients experiencing shocking blurriness or blindness, we typically find previous red flags they ignored, put off attending to, or didn’t realize were serious. 

6 Potential Reasons For Sudden Vision Loss In One Or Both Eyes

Honoring your routine annual eye exams and checking in with your optometrist about any changes in eye comfort or vision changes is the best way to prevent the risk of sudden blindness in one or both eyes. Here are six of the most common causes.


Migraines are the number 1 reason for temporary, partial sudden vision loss. While most migraines are associated with extreme headaches, others are purely visual, called “ocular migraines.” In addition, most migraines are associated with some type of visual “aura,” which may include flashing lights, blind spots, or shimmering blurriness. 

Usually, ocular migraines resolve within 30-minutes to an hour, even though the headache can last longer. If you’re prone to ocular migraines, let your eye doctor know. Detailed descriptions of the symptoms and answers to other questions can help us identify avoidable triggers and personalized treatments or medications.

Severe dry eye

Dry eye is becoming an optometric epidemic of sorts. More and more patients are diagnosed with dry eye each year, largely due to increased screen time. Dry eye leads to corneal scarring that can cause permanent vision loss when left unaddressed.

Symptoms of dry eye include:

  • Dry eyes
  • A feeling of grit or sand in the eyes
  • Red, inflamed eyes or eyelids
  • Excessive tearing
  • Fluctuating vision that improves with blinking rapidly or readjusting vision 

Treatment for dry eyes may be as simple as taking healthy screen breaks, consciously blinking more (especially while on screens or watching TV), and using preservative-free artificial tears. In more serious cases of dry eye, an optometrist may prescribe prescription eye medications to reduce eye inflammation.

Note: People with dry eyes tend to rub their eyes more, which compounds the problem because it scratches the cornea. Always use eye drops or warm, moist compresses in lieu of rubbing, and schedule that appointment with your eye doctor!

Eye trauma can cause sudden vision loss

In many cases, minor eye trauma is a DIY treatment situation. However, sometimes trauma to the eye leads to temporary or permanent vision loss. However, a medical professional or optometrist should immediately examine any major eye injury or minor eye trauma followed by unresolved or worsening symptoms.

Retinal tears or retinal detachment

The retina is made up of delicate layers. As we age or as a result of eye trauma, some or all of these layers can begin to tear or pull away from the back of the eye. It is most common in adults 50+ but can happen to younger patients. The most common symptoms of retinal detachment include the sudden appearance of floaters and flashes, black spots in the field of vision, blurred/darker/dimmer vision, and loss of peripheral vision.

Complete blindness can ensue if previous symptoms are ignored due to the build-up of successive scar tissue. Retinal tears and retinal detachment are repaired using surgery, cryotherapy, or vitrectomy (we drain the fluid in the middle of the eye and replace it).

Cortical cataracts

Most cataracts develop slowly over time, causing gradual blurriness, dimming, and vision loss. However, there are cases where cataracts develop more quickly and grow across the center of the lens. This can lead to dramatic vision loss over the course of a few weeks.

The good news is that cataract surgery successfully treats cortical cataracts for patients in relatively good health.

Retinal vein occlusion

Sometimes a blood clot gets lodged in the retina, called retinal vein occlusion. This is like a stroke that happens in the eye instead of the brain. When retinal vein occlusion occurs, it can cause partial or full blindness in the affected eye. Most of the time, symptoms of retinal vein occlusion occur several days before vision is lost completely, including swelling or fluid leakage in the eye, as well as fluctuating vision changes. Retinal vein occlusion is very rare but occurs most often in patients with diabetes or health issues that affect blood pressure.  

Additional Causes Of Rapid Vision Loss

Other potential causes of rapid vision loss or blurred vision include:

  • An eye infection. If you have a bacterial, viral, or fungal eye infection, especially one that hits during allergy season, inflammation can lead to blurry vision quickly. Most eye infections are easily treated using the right drops, but an accurate diagnosis is essential. Using antibacterial eye drops won’t help if a virus or fungus causes the infection, and you can wind up making the infection worse.
  • Giant cell arteritis (GCA). This condition is most often found in the elderly population, occurring when blood vessels in the scalp are inflamed. If the arteries feeding the optic nerve are affected, blood flow to the optic nerve is compromised, leading to irreversible vision loss. Patients with GCA should keep in close contact with their optometrist/ophthalmologist and look out for early symptoms like headaches and eye tenderness. Steroidal drops can provide relief and can prevent the condition from worsening.
  • Retinal vasospasm. If the veins feeding the retina start to spasm, it causes temporary vision loss. This is most common in patients with high blood pressure or hardening/narrowing of the arteries (atherosclerosis). You may experience a migraine as well, which is a reason why a physician or optometrist should always assess migraines.
  • Closed-angle glaucoma. In this version of glaucoma, increased pressure in the eye causes the iris to bulge. Patients with closed-angle glaucoma causing vision loss typically experience nausea, eye discomfort, and vision loss.

Contact An Optometrist ASAP When Experiencing Sudden Vision Loss

Vision is precious and many conditions leading to sudden vision loss need immediate attention to prevent irreversible damage Contact Eye to Eye Family Eye Care, at 918-227-3937, if you or someone you love experiences sudden vision loss or any abnormal eye symptoms.