The instrument below is called a slit lamp. It is a necessary piece of equipment to determine what is wrong if there is any sort of eye irritation, pain, or redness. So if you have these symptoms and go to your PCP or urgent care and they do not look at your eyes with this instrument and instead just call it "pink eye" and Rx antibiotic eyedrops with no follow-up, I'd recommend a second opinion. Without this instrument, there is actually no way to tell if your eye pain/redness is due to an acute angle closure glaucoma attack (rare, but can cause permanent vision loss rapidly) versus a corneal ulcer (which also can cause vision loss and is fairly common in contact lens wearers especially if the contacts are being slept in/overworn) versus iritis (which sometimes may be the first sign of more serious systemic disease) versus a tiny piece of maybe wood or metal lodged in the cornea. Or something else. Without looking with this instrument, there's really no way to know.
