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Visualizing Visual Impairments

See Through the Eyes of Someone With an Eye Disease

With most severe eye diseases, you may not have symptoms until the disease is advanced.

“Most eye diseases exist in the background, but are very treatable if caught early,” says Northwestern Medicine Neuro-ophthalmologist Nicholas J. Volpe, MD. “That’s why it’s so important to get yearly eye exams and know your family history so that you can give yourself the opportunity to receive treatment.”

Here are some common eye diseases and how they can affect your vision.


What they are: Buildup of proteins that cause cloudiness and change in color of the lens of the eye.

Effect on vision:

  • Glare or halos around lights, especially at night
  • Gradual clouding
  • Frequent glasses prescription changes
  • Developing more nearsighted vision
  • Dimmer with a slight yellow or brown hue
  • Lack of contrast


  • Aging
  • Long-term steroid use
  • Uveitis, or inflammation of the eye
  • Diabetes
  • Trauma to the eye
  • Smoking
  • Excessive exposure to sunlight
  • Previous eye surgery
  • Genetics
  • Certain medications

Treatment: Surgery to replace the affected lens(es).


What it is: Fluid buildup in the eyes causes pressure, damaging the optic nerve.

  • The optic nerve contains millions of tiny nerve fibers.
  • As the pressure damages these fibers, you begin to develop blind spots in your vision.
  • You may not notice this until most of your optic nerve has been damaged.

Effect on vision:

  • Peripheral vision loss can be so slow you may not realize it is happening (no symptoms)
  • Early stages: loss of peripheral vision (central vision remains clear until late stages)
  • Late stages: loss of central vision and peripheral vision
    • Vision remains as an arc around the center of your sight.
  • Arc of vision may be muted or darker
  • Can cause top or bottom blindness, meaning you may lose the top or bottom of your visual field
  • Can cause total blindness


  • Genetics: Family history is a major risk factor
  • Previous trauma
  • Uveitis or intraocular inflammation
  • Exists in an acute form with sudden increase in pressure as a result of angle closure (painful with acute vision loss)


  • Routine screening to detect glaucoma if positive family history
  • Medication (eyedrops) to lower eye pressure or reduce fluid in the eyes
  • Surgery to help fluid drain from the eye(s)

Ischemic Optic Neuropathy

What it is: Blood flow is blocked to your optic nerve.

Effect on vision: Loss of large section of vision, often the bottom half

Cause: Swelling or blockage of arteries going to your optic nerve


  • In some case, steroids to reduce swelling
  • Management of underlying issues like high blood pressure and diabetes

Macular Degeneration

What it is: Age-related deterioration of the macula, which is at the center of the retina and allows your eyes to see sharp details.

There are two types of macular degeneration: dry and wet.

  • Dry: Light-sensitive cells in the macula deteriorate over time.
  • Wet: Blood vessels underneath the retina leak into and under the retina, creating a blind spot and other irregularities in the center of your vision.

Effect on vision:

  • Early stages: loss of central visual clarity
    • Distortion of shapes; for example, straight lines will have bends
  • Late stages:
    • Center area of vision will become increasingly unclear, small blind spots, difficulty reading
    • Over time, vision will become distorted
    • Eventually can lead to central loss of vision, but peripheral vision not affected


  • Genetic predisposition, more likely to get it if first degree family member affected
  • Sunlight exposure over a lifetime
  • Lack of healthy diet rich in foods with antioxidants
  • Smoking


  • Certain patients benefit from specific nutritional supplements to slow the progression of dry macular degeneration.
  • Treatment options for wet macular degeneration include ocular injections to minimize fluid leakage and swelling and laser surgery to seal leaking blood vessels.

Posterior Vitreous Detachment (Floaters)

What it is: Gel that fills the eye separates from the retina, the light-sensing structure at the back of the eye.

Effect on vision:

  • Shapes that appear to be like small circles or bugs suddenly appear and float through vision.
  • You may see flashes of light.
  • Vision improves when you move your eyes and floater moves away.
  • Floaters move in the opposite direction of your eyes when you scan the environment.


  • Age and normal deterioration
    • Over time, the gel that fills the eye condenses and separates from the retina in little pieces.


  • Important to get a complete eye examination with pupil dilation to be certain that posterior vitreous separation did not cause a hole or tear in the retina, which could lead to retinal detachment.
  • If exam does not show damage to the retina, this is a non-vision-threatening disease that may clear up on its own.
  • Worsening of symptoms (increased floaters, flashes or shadows in vision) should prompt urgent reexamination.


What it is: Interruption of blood flow to the brain due to a blood clot or bleeding, which can damage parts of the brain that control vision.

Effect on vision:

  • Sudden loss of vision
  • Loss of the same half of your vision in both eyes
    • If the right side of your brain is affected, you will lose left-side vision; if the left side is affected, you will lose right-side vision.
    • Vision loss can be the only symptom of a stroke.


  • Ischemic strokes occur when a blood clot blocks blood flow to the brain.
  • Hemorrhagic strokes occur when a brain aneurysm or blood vessel bursts; this causes blood to spill into or around the brain, which creates swelling and pressure.

Treatment: Patients with sudden loss of vision should call 911 to be examined for stroke. Learn about other symptoms of stroke.

Diabetic Retinopathy

What it is: Damage to the blood vessels in the light-sensing back of the eye (retina).

Effect on vision:

  • No symptoms in early stages
  • Blurred vision
  • Web of floaters
  • Back streaks in vision
  • Dim vision in later stages
  • Difficulty seeing colors
  • Total blindness may occur

Cause: Complication of diabetes


  • Careful screening eye exams needed at least yearly for all people with diabetes, regardless of whether they have vision symptoms
  • Intraocular injections or laser therapy if retinopathy develops
  • Diabetes management: Tight control of blood glucose reduces both the risk and severity of diabetic retinopathy

Retinitis Pigmentosa (RP)

What it is: Condition that changes how the retina responds to light.

Effect on vision:

  • Loss of night vision (cannot see anything in the dark)
  • Loss of peripheral vision
  • Loss of central vision

Cause: Genetic condition caused by more than 100 different genes

Treatment: Depends on the gene that is causing it

Retinal Detachment

What it is: Separation of retina from the back of the eye.

Effect on vision:

  • Flashing or floaters often precede loss of section of vision
  • Progresses to partial or total vision loss in one eye


  • Increased likelihood with age
  • More common in near-sighted people, but most often develops spontaneously because of retinal tear
  • Trauma or previous eye surgery

Treatment: Immediate evaluation and surgery

Bottom Line

“Many blinding eye diseases have no visual symptoms or pain early on, and almost all are treatable,” says Dr. Volpe. “These diseases are highly treatable if caught early, but sometimes not treatable if caught too late. That’s why your yearly eye exam is so important.”

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