This is inflammation of the optic nerve, often linked to multiple sclerosis (MS) or autoimmune conditions. It typically causes:

Sudden blurred or lost vision in one eye
Pain when moving the eye
Optic neuritis can be an early sign of MS, so any sudden vision issues must be medically assessed right away.

3. Transient Ischemic Attack (TIA)

Commonly referred to as a “mini-stroke,” a TIA temporarily cuts off blood flow to part of the brain.

Wa:r:ning signs may include:

Sudden vision changes or loss in one eye
Difficulty speaking
Weakness or numbness in one side of the body

A TIA is a medical emergency and a serious red flag for a future stroke. If you notice these symptoms, call emergency services immediately.

4. Retinal Disorders

Issues involving the retina — such as retinal detachment or retinal vein occlusion — can also lead to:

Vision loss or blurriness in one eye
Flashes of light
Floating spots or “shadows” in your field of vision