The information contained herein is not intended as a substitute for medical advice and care from qualified doctors of optometry. The reader should regularly consult a doctor in matters relating to his or her health and particularly with respect to any symptoms that may require diagnosis or medical attention. 

• What is 20/20 vision?
  
• Is 25/25 vision better than 20/20?
  
• Why do some people have less than 20/20?
  
• If my vision is less than optimum, what can I do?
  
• When should children have their vision checked?
  
• What is astigmatism?
  
• What is nearsightedness?
  
• What is farsightedness?
  
• What is presbyopia?
  
• What are spots, floaters, and flashes?
  
• What is color blindness?
  
• What is double vision?
  
• What is glaucoma?
  
• What is a cataract?
  
• What is keratoconus (conical cornea)?
  
• What is dry eye?
  
• What is conjunctivitis?
  
• What is a stye?
  
• Are contacts for you?
  
• What are the advantages of wearing contact lenses?
  
• What are the disadvantages of wearing contact lenses?
  
• How do contact lenses correct vision?
  
• Why replace contact lenses frequently?
  
• When can you begin wearing contact lenses?
  
• Colored contacts
  
• Can I store contact lenses in tap water?
  
• Can I lose a lens behind my eye?
  
• How can I tell if I have the lens in the wrong eye?
  
• How can I tell if a soft lens is inside out?
  
• My lens has a very small chip or tear in the edge but it doesn't bother me. Should I replace it anyway?
  
• How do I know when to dispose of disposable lenses? They seem to be OK longer than I expected.
  
• My eyes get dry. What kind of eye drops can I use?
  
• There are so many solutions out there, how do I know which is best?

What is color blindness?

Color blindness is a vision defect in which colors are not seen normally. The various degrees of color blindness are caused by the state of the color receptors found at the back of the eye. While there is no cure for color blindness, personalized methods of color identification and visual aids can help color-blind people. Parents, employers, and color-blind people themselves all have a role to play in ensuring that environments are as safe and user-friendly as possible.