Blindness

Blindness refers to complete or nearly complete vision loss that cannot be corrected with glasses or contact lenses. It can develop suddenly or gradually, affect one or both eyes, and range from partial to total loss of sight. Understanding the warning signs and causes of vision loss is crucial, as some forms of blindness are preventable or treatable if caught early.

⚠️ VISION EMERGENCY - Seek Immediate Care For:

  • Sudden complete vision loss in one or both eyes
  • Vision loss with severe eye pain
  • Sudden "curtain" or "shadow" over vision
  • Vision loss after head or eye injury
  • Flashing lights followed by vision loss
  • Vision loss with severe headache
  • Chemical splash in eyes
  • Vision loss with stroke symptoms
  • Sudden blind spots or dark areas
  • Vision loss in diabetics

Time is critical - many causes of sudden blindness require treatment within hours to preserve vision.

Types of Vision Loss

Blindness encompasses various degrees and types of vision loss. Legal blindness is defined as visual acuity of 20/200 or worse in the better eye with correction, or a visual field of 20 degrees or less. Total blindness means complete lack of light perception, while partial blindness includes various levels of remaining vision.

Vision loss can be categorized by onset (sudden vs. gradual), extent (partial vs. complete), duration (temporary vs. permanent), and affected area (central vs. peripheral). The pattern and progression provide important diagnostic clues about the underlying cause.

Common Causes

Eye Diseases

  • Glaucoma
  • Macular degeneration
  • Diabetic retinopathy
  • Cataracts
  • Retinal detachment
  • Optic neuritis

Vascular Causes

  • Stroke affecting vision
  • Retinal artery occlusion
  • Retinal vein occlusion
  • Giant cell arteritis
  • Ischemic optic neuropathy
  • Hypertensive retinopathy

Trauma/Injury

  • Eye injuries
  • Head trauma
  • Chemical burns
  • Radiation damage
  • Foreign body
  • Corneal abrasion

Other Causes

  • Congenital conditions
  • Brain tumors
  • Multiple sclerosis
  • Vitamin A deficiency
  • Infections (CMV, toxoplasmosis)
  • Medication side effects

Warning Signs Before Vision Loss

  • Blurred vision: Progressive worsening
  • Halos around lights: Glaucoma sign
  • Floaters: Sudden increase
  • Flashing lights: Retinal issues
  • Night blindness: Difficulty in low light
  • Tunnel vision: Loss of peripheral sight
  • Double vision: Neurological causes
  • Eye pain: With vision changes

Patterns of Vision Loss

Central Vision Loss

  • Macular degeneration
  • Macular hole
  • Diabetic macular edema
  • Central retinal vein occlusion

Peripheral Vision Loss

  • Glaucoma
  • Retinitis pigmentosa
  • Stroke
  • Brain tumors

Patchy Vision Loss

  • Diabetic retinopathy
  • Branch retinal vein occlusion
  • Age-related changes
  • Optic nerve damage

Diagnostic Approach

Immediate Assessment

  • Visual acuity testing
  • Pupil examination
  • Eye pressure measurement
  • Visual field testing
  • Ophthalmoscopy
  • Slit lamp examination

Advanced Testing

  • OCT scan: Retinal imaging
  • Fluorescein angiography: Blood vessel evaluation
  • ERG: Retinal function
  • VEP: Optic nerve function
  • MRI/CT: Brain and orbit imaging
  • Blood tests: Systemic causes

Treatment Approaches

Medical Treatment

  • Anti-VEGF injections
  • Steroid medications
  • Glaucoma drops
  • Antibiotics for infections
  • Anti-inflammatory drugs
  • Blood pressure control
  • Diabetes management
  • Vitamin supplements

Surgical Options

  • Cataract surgery
  • Retinal detachment repair
  • Vitrectomy
  • Corneal transplant
  • Glaucoma surgery
  • Laser treatments
  • Tumor removal
  • Shunt placement

Living with Vision Loss

Adaptive Strategies

  • Vision rehabilitation training
  • Mobility training with white cane
  • Guide dog services
  • Assistive technology
  • Screen readers and magnifiers
  • Braille education
  • Home modifications
  • Support groups

Available Resources

  • Low vision specialists
  • Occupational therapy
  • State blind services
  • National Federation of the Blind
  • Lighthouse organizations
  • Vocational rehabilitation

Prevention Strategies

  • Regular eye exams: Annual comprehensive exams
  • Manage health conditions: Diabetes, hypertension
  • Eye protection: Safety glasses, sunglasses
  • Healthy lifestyle: Diet rich in vitamins
  • Quit smoking: Major risk factor
  • Know family history: Genetic conditions
  • Early treatment: Address problems promptly
  • Monitor medications: Some affect vision

Related Symptoms

Blurred Vision

Often precedes vision loss.

Eye Pain

May accompany vision loss.

Double Vision

Neurological vision problem.

Diminished Vision

Partial vision loss.