Wendy from Pullman asks is there a difference between visual field machines?

Wendy, because the field of vision from each eye overlaps, it is very difficult for your brain to realize it is missing some areas and while there are many different types of field machines, they all are used to measure your visual field; what you can or can not see out of each eye. Some have a static spot where you fixate on a spot and respond when you see flashes of light. While in others the fixation point moves so you follow it and respond to the flashes in that way. Sometimes we just a want a screening test, a very quick test and other we want something much more precise which takes longer. While the machines are very important tools that can precisely measure changes in your vision due to glaucoma, brain tumors or toxic effects of medicines, it is still up to your eyecare professional to interpret those results. Thanks for the question.