Vision Problems

1. Myopia, also known as near-sightedness, is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it, causing the image that one sees when looking at a distant object to be out of focus.
   
   

   
   
2. Hyperopia, commonly known as farsightedness, is a defect of vision caused by an imperfection in the eye (often when the eyeball is too short or the lens cannot become round enough), causing difficulty focusing on near objects.
   
   

   
   
3. An optical system with astigmatism is one where rays that propagate in two perpendicular planes have different focus.
   
   

   Astigmatism

   
   
4. Presbyopia is a condition associated with aging in which the eye exhibits a progressively diminished ability to focus on near objects. Evidence most strongly supports a loss of elasticity of the crystalline lens as its cause.
5. A cataract is a clouding of the lens in the eye leading to a decrease in vision.
6. Glaucoma is a spectrum of diseases causing a chronic progressive optic neuropathy which is characterised by optic nerve damage and visual field loss.