eye disease

• What is color blindness?

  when a person has difficulty distinguishing between red and green.

  
• why does a person with color blindness not see between red and green?

  because of the lack of receptors in the retina
• when an eye cannot focus an objects image on a single point on a retina.

  astigmatism

  
• in astigmatism the cornea is

  oval instead of spherical.

  
• astigmatism causes

  blurred vison

  
• glaucoma affects the

  optic nerve pressure
• to prevent glaucoma you should

  check your eyes regularly as it can be treated.
• glaucoma is the

  loss of ganglion cells
• glaucoma could result in

  gradual loss of sight and eventual blindness
• clouding forms in lens due to denaturing of lens proteins

  cataracts
• cataracts obstruct the

  passage of light.
• cataracts are caused by

  age ,chronic exposure to UV light
• cataracts can be removed by

  surgery