Causes of Sudden Blurred Vision in One Eye and What to Do Next

When Vision Suddenly Blurs - What Does Blurred Vision in One Eye Mean?

Blurred vision can occur anytime and without warning - and if it affects only one eye, it can be all the more concerning. Sudden deterioration in visual acuity, especially in just one eye, should not be underestimated. Although the cause may not always be serious, in some cases, it may be a symptom of a serious condition requiring immediate medical attention.

Blurred vision in one eye can have a wide range of causes - from fatigue or dry eye to a stroke or retinal detachment. It depends on accompanying symptoms, overall health condition, and the speed at which the issues appear. It's not just a problem for older people - younger individuals may also experience this phenomenon.

What Can Cause Sudden Worsening of Vision in One Eye?

Loss of visual acuity can be temporary or permanent. For instance, if you spend several hours in front of a screen and forget to blink, tired eyes may temporarily react with blurred vision. However, if the blurring appears suddenly without an apparent cause and does not disappear after rest or blinking, it is necessary to be vigilant.

One of the common reasons is dry eye, which occurs with insufficient tear production or rapid evaporation. This can happen during prolonged computer work, staying in air-conditioned rooms, or taking certain medications. In this case, blurring is usually accompanied by a burning sensation, pressure in the eye, or itching.

Another more common cause is refractive errors, which are poor focusing of light on the retina, such as nearsightedness, farsightedness, or astigmatism. If you wear glasses and suddenly experience worsened vision in one eye, the problem may be in a damaged lens or a change in eye proportions - for example, due to aging.

But what if the vision blurs really suddenly - within seconds or minutes - and does not return? In such a case, it may be a sign of an acute health condition.

When Time is of the Essence - More Serious Diagnoses

One of the key causes of sudden blurred vision in one eye is so-called ischemic optic neuropathy. This condition occurs when there is an interruption or limitation of blood flow to the optic nerve. It usually appears in people over 50, often in connection with high blood pressure, diabetes, or arteritis. The image suddenly darkens, blurs, or the entire field of vision disappears.

Another dangerous phenomenon is retinal detachment. The retina is a thin layer of tissue that captures light and sends signals to the brain. When it detaches from surrounding layers, it can lead to permanent vision loss. The first symptom is often blurred vision, the appearance of "floaters" in front of the eye, or flashes of light. If the sensation of "curtains falling" over the visual field is added, it is a reason for an immediate visit to the doctor.

A lesser-known but serious problem can also be a stroke affecting the visual center. Although most people associate a stroke with paralysis or speech disorders, in some cases, the only symptom may be blurred or lost vision in one eye. In such moments, the speed of intervention is crucial - according to medical research, there is a so-called "golden hour" during which timely treatment can significantly reduce the risk of permanent damage.

When Eyes Speak About the Body

Vision is often a mirror of overall health. Diseases such as diabetes (diabetic retinopathy), multiple sclerosis, or autoimmune inflammation can show the first signs in the eyes. In the case of multiple sclerosis, a sudden inflammatory attack on the optic nerve (optic neuritis) may occur, leading to painful blurring or vision loss - usually unilaterally.

An interesting case involves people suffering from migraines. It's not just about headaches - so-called ocular migraines can cause temporary blurring or loss of vision in one eye, often accompanied by visual effects (flashing, sparkling, zig-zag lines). Although this condition usually subsides over time, it can be very unsettling.

A similar experience was shared by Mrs. Ivana, a 38-year-old teacher from Brno. "One day I was sitting in the office, and suddenly it started to blur in front of one eye. At first, I thought it was just fatigue. But then I noticed some floating spots in my field of vision. I went straight to the eye emergency room, and it turned out I had a small blood vessel burst in my eye. Fortunately, it was without permanent consequences, but it scared me a lot." Her case shows how important it is to perceive even seemingly minor changes as a potential signal of a bigger problem.

When to See a Doctor and What to Expect

When blurred vision in one eye suddenly appears, it is definitely not something to overlook. Especially if it is accompanied by eye pain, headache, flashes, field of vision loss, or perhaps nausea. If it doesn't resolve within a few minutes, lasts longer, or even repeats, don't hesitate to seek help - even if it seems to have appeared for no reason.

In these cases, it is advisable not to wait and visit emergency care, or call for urgent assistance. An eye doctor will usually dilate the pupil, measure intraocular pressure, check the retina, and perform visual acuity tests. In some cases, it is necessary to supplement with a neurological examination or a CT/MRI of the brain, especially if there is a suspicion of a vascular or neurological cause.

What Can We Do for Prevention?

Eye care is part of overall health prevention. Although we cannot influence all risk factors, there are steps that can help protect the eyes:

• Regular eye exams - even if you don't have prescription lenses, a check-up at least once every two years can detect problems early
• Healthy lifestyle - a balanced diet rich in vitamins A, C, E, omega-3 fatty acids, and lutein can strengthen eye health
• Protection against UV radiation - quality sunglasses with a UV filter are an investment in the future
• Hydration and hygiene - sufficient fluid intake and a quality environment for the eyes (dust-free, with enough humidity) help against dryness
• Limiting screen time - the 20-20-20 rule (every 20 minutes look at something 20 feet away for 20 seconds) can alleviate digital fatigue

Prompt response to visual changes can prevent serious consequences. As the renowned British ophthalmologist Professor Chris Hammond says: "Vision problems are often the first signs of something bigger. Ignoring them means overlooking potentially serious illness."

Vision is one of the most valuable senses we have - and that's why it deserves attention. Sudden blurred vision in one eye is not just a trifle but a potentially warning signal. Noticing changes and not postponing an examination can be key to maintaining good vision and quality of life.