Why It Happens and How to React

Il·lustració pèrdua de visió en una imatge de paisatge

A sudden vision loss may be alarming for someone experiencing it. It is an emergency that should be immediately checked by specialized medical professionals. That is why if you loose sight all of a sudden (images get blurry, your vision stops being clear, you totally o partially loose your visual field) in a matter of minutes, hours or even a few days, it is very important that you go to the ophthalmology emergency room, open 24 hours, 365 days a year.

During the consultation, the medical team may help identify which of the two eyes has lost sight, if you have not been able to not determine that sooner, covering them alternatively. Moreover, your case will be examined and the cause of it will be determined, defining the necessary treatment.

Possible Causes of a Sudden Vision Loss

The causes of sudden vision loss in one or both eyes can vary widely:

  • Optical neuritis or optic disc, usually due to an autoimmune reaction.
  • Ocular migraine, a condition that is often accompanied by the headaches caused by migraines and that typically affects only one eye. People with this condition often experience blind spots (scotomas) and, occasionally, visual disturbances involving light.
  • Retinal detachment. A portion of the retina detaches, causing the person to see a black spot in their visual field. Sometimes, they first see other spots or flashes of light, similar to those from a camera. It is important to seek emergency treatment.
  • Vitreous hemorrhage, the presence of blood in the vitreous humor, which obscures the visual field and impairs vision. It is common in patients with diabetes.
  • Eye strain or stress, which clouds or blurs vision, causing primarily blurred vision rather than a loss of vision.
  • Glaucoma, specifically acute angle-closure glaucoma, which can cause a sudden increase in intraocular pressure in one eye, usually accompanied by headache, nausea, and vomiting.
  • Obstructions of blood flow in the arteries or veins of the retina, which prevent it from functioning properly.
  • Retinal infections and endophthalmitis. In addition to vision loss, these can also cause pain, a red eye, or myodesopsia (see floaters).

What Can I Do if I Experience Sudden Vision Loss?

As mentioned at the beginning of this article, the most important thing to do if you experience a sudden loss of vision is to identify which eye is affected and seek urgent care at an ophthalmology center. The medical staff will be able to determine the cause of the problem and prescribe the most appropriate treatment for each case.

To make an accurate diagnosis, the medical team will perform a comprehensive eye exam, which may include several tests. In some cases, general tests—such as neurological exams or blood tests—may also be necessary.

Treatments for sudden vision loss may include medication, such as eye drops, intravitreal injections, or even surgery, which in some cases must be performed on an emergency basis. Systemic treatment may also be necessary, requiring the involvement of other medical specialties.

In some cases, visual acuity may even recover on its own. In others, depending on the cause and how quickly treatment is administered, vision loss may be reduced or even reversed.

Medical content validated on 22/04/2026 by:
Cataract, Glaucoma

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