if lasers can perform such tasks as the delicate task of mending someones eye and abeling someone to see, why cant they

Question: if lasers can perform such tasks as the delicate task of mending someones eye and abeling someone to see, why cant they be uised for hundreds of more tasks, for example helping to adapt different organisms, changing the structure of germs so they dont make us ill etc. ?
- Keywords:
  delicate,
  eye,
  germ,
  ill,
  mend,
  organism,
  perform,
  structure
Asked by rbgrhetkj to Mike, Pip, Tianfu, Tim, Tom on 2 Jul 2012.
- Tom Lister answered on 2 Jul 2012:
  
  Fixing somebody’s eyesight is a mechanical task, it works by reshaping their cornea (which does most of the focussing of light by the eye). In this way, it is used like a very precise knife. If there are other tasks, like manipulating individual organisms, which require some cutting or heating, then lasers could be used. I think most of these things can be done more easily by adding chemicals or by using very small glass tools, and scientists do like to choose the easiest ways of doing things if they can!
- Tim Stephens answered on 4 Jul 2012:
  
  Yup. You always use the tool that’s best for the job. I guess the reason that lasers aren’t used for these things at the moment is that there are other tools that do the job better (or more cheaply).

Question: if lasers can perform such tasks as the delicate task of mending someones eye and abeling someone to see, why cant they be uised for hundreds of more tasks, for example helping to adapt different organisms, changing the structure of germs so they dont make us ill etc. ?