Blindness or Loss of Vision

Eyes | Ophthalmology | Blindness or Loss of Vision (Symptom)


Vision loss or visual loss is the absence of vision where it existed before, which can happen either acutely (abruptly) or chronically (over a long period of time). Vision loss implies any degradation in the ability to see, including blurred vision, cloudy vision, double vision, blind spots, poor night vision, and loss of peripheral vision (tunnel vision). Vision loss may affect one or both eyes, it may occur gradually or suddenly, and it may be partial or complete.


Vision changes may originate in the eyes themselves or may be caused by many different conditions that affect the brain or even the whole body.

Some usual causes of vision loss are eye trauma, clouding of the lens known as cataract, increased eye pressure or glaucoma, retinal damage due to diabetes called diabetic retinopathy, breakdown of the central portion of the retina (age-related macular degeneration), retinal detachment, inflammation of the optic nerve (optic neuritis), and stroke. Vision can also be affected by some medications.

Vision loss may accompany other symptoms, which will vary depending on the underlying disease, disorder or condition. Conditions that affect vision can also involve other body systems. Vision loss may accompany other symptoms affecting the eye including: dilated pupils or pupils that do not respond to light, discharge from the eye, eye pain, increased sensitivity to light, itchy eye, red, sore eyes (bloodshot eyes), white pupil.

Diagnosis and Treatment

Blindness is diagnosed by visual acuity testing in each eye individually and by measuring the visual field or peripheral vision. Patients may have unilateral blindness (in one eye) or bilateral blindness (both eyes). Historical information regarding the blindness can be helpful in diagnosing the cause of blindness.

Treatment depends on the underlying cause. If the loss of vision cannot be corrected, the patient may then be registered as legally blind or partially sighted.