This is the machine we use to check your glasses prescription. It is filled with lenses that we flip in front of your eyes, saying “one or two” the whole time as you read the eye chart. The phoropter is the best way to refine an eyeglass prescription, as we can use this machine to detect and fix your astigmatism as well. Unfortunately, some of our patients can’t use the phoropter machine because it requires a certain amount of subjective feedback. Young children and the infirm may need to be checked with less precise measurements such as the retinoscope.