how does the glass in glasses change how you see? :)

Question: how does the glass in glasses change how you see? :)
- Keywords:
  glass,
  glasses
Asked by tashi.x to Adrian, Gaia, Jim, Scott, Vicky on 9 Mar 2016. This question was also asked by 679rdme25.
- Gaia Andreoletti answered on 9 Mar 2016:
  
  Glasses lens is curved so that it bends the light rays that hit your eyes so you can see images clearly.More precisely glasses correct vision because they allow the eye to focus light in the right spot on the retina, the clear tissue that helps the eye focus.
- Scott Lawrie answered on 9 Mar 2016:
  
  Have you ever seen in your science text books a picture of an eye? It’s quite a clever thing! It’s got a lens in the front that looks a lot like the glass in your glasses. In front of the lens is your pupil which gets bigger and smaller depending on how dark it is in the room. Behind the lens is the retina which turns the light you see into a picture your brain can understand.
  
  If the lens is the wrong shape, the picture the retina makes isn’t right, so it might look blurry to your brain. An optician can tell how wrong your lens is and make some glasses which help make the picture better.

Question: how does the glass in glasses change how you see? :)