TYPES OF LOW VISION

• Loss of Central Vision – The loss of central vision creates a blur or blindspot, but side (peripheral) vision remains intact. This makes it difficult to read, recognize faces, and distinguish most details in the distance. Mobility, however, is usually unaffected because side vision remains intact.
  
  
• Loss of Peripheral (Side) Vision – Loss of peripheral vision is typified by an inability to distinguish anything to one side or both sides, or anything directly above and/or below eye level. Central vision remains, however, making it possible to see directly ahead. Typically, loss of peripheral vision may affect mobility and if severe, can slow reading speed as a result of seeing only a few words at a time. This is sometimes referred to as "tunnel vision."
  
  
• Blurred Vision – Blurred vision causes both near and far to appear to be out of focus, even with the best conventional spectacle correction possible.
  
  
• Generalized Haze – Generalized haze causes the sensation of a film or glare that may extend over the entire viewing field.
  
  
• Extreme Light Sensitivity – Extreme light sensitivity exists when standard levels of illumination overwhelm the visual system, producing a washed out image and/or glare disability. People with extreme light sensitivity may actually suffer pain or discomfort from relatively normal levels of illumination.
  
  
• Night Blindness – Night blindness results in inability to see outside at night under starlight or moonlight, or in dimly lighted interior areas such as movie theaters or restaurants.

http://www.aoa.org/x5244.xml