Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Medical What is that machine at the opthamologist's clinic?

  1. Jan 26, 2008 #1
    i went to an opthamologist today for an eye checkup.. and his assistant told me to put my chin on some machine and that machine sort of showed me an image of some scenery sort of thing. Now, the machine started to do something.. and i could see the image getting blurred again and becoming sharp again. It finally stopped at some point where the image became sharp. Then it did the same thing for the other eye. The assistant then noted down some numbers from that machine.

    what exactly does that machine do, what's it's name.. and how does it know when my eyes see a perfectly sharp image?
  2. jcsd
  3. Jan 26, 2008 #2


    User Avatar
    Gold Member

    That's an auto-refractor. It gets a quick and dirty reading of the eyes, and generally they spit out a little print-out with your refractive errors (if any) that is attached to your chart, so that when you get shown to an exam room, the ophthalmologist's assistant will have a very close starting point to set the phoropter (that machine that you look through with lots of lenses set in internal wheels... "is this better, or this?"). This saves time in the exam room, so the doctor can examine more people in the course of the day.
  4. Jan 26, 2008 #3
    thx a lot man.. now that i have the name of the machine.. i'll go wikip it :D
  5. Jan 29, 2008 #4
    I went to the doctor again for a checkup... and he took a lens holder of some sort and pointed a torch through it into my eye. I could see two circular arcs of light going up and down along the rim of the lens.

    what exactly was he doing? Was he trying to dilate my pupils or something??
  6. Jan 29, 2008 #5


    User Avatar
    Gold Member

    Was your chin in a chin rest, and was he pivoting that bright light from side-to-side while looking into your pupil with another instrument? If so, that bright light was from a slit lamp.

  7. Jan 29, 2008 #6
  8. Jan 30, 2008 #7
    Retinoscopy is the term for that. It does the same thing as the machine(auto-refractor). Sometimes there is an artifact or an error with the auto-refractor reading then it must be rechecked manually by retinoscopy.
    Last edited: Jan 30, 2008
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: What is that machine at the opthamologist's clinic?