You didn't happen to take an antibiotic in the last couple of years called keflex, did you?  It is also called cephalexin, cefepime, etc.  An allergic reaction to it caused me to have terrible dry eye for 3 years.  

is the eye pain really a emergency?

Hi, Juli, sorry, it was late when I wrote this and didn't realize it was you.  I don't know if eye pain is something to consider an emergency.  I would talk to an advice nurse to get an opinion.  Has your doctor sent you to an opthalmologist to check for serious conditions?  I would also do a search on google and on the mayo clinic website for dry eyes to get an idea of what might be causing it.  The only thing that could be done for my dry eyes after I took cephalexin was to stop the cephalexin after only 3.5 days.  I went to an opthamologist and she didn't find anything.  I often tended to just close my eyes and try to let them rehydrate.  It took three years for my eyes to feel fairly normal again, and it wasn't till after my vitamin D deficiency got corrected that my over-sensitivity to light resolved itself.  Another person who had the same thing happen after taking keflex got relief from a prescription from her doctor.  I believe it was restasis.  Her eyes were in pretty bad shape in terms of dryness for about three years as well.  Neither of us remember any pain except the oversensitivity to light.  Is the pain that you are experiencing only when you are exposed to light, like a bedside light, sun, etc.? 

Hi, Juli, I got your post on my profile. I have a feeling that the ER will tell you they can't do anything, but it's up to you what you want to do. Knowing what I know now about keflex/cephalexin and how it affected my eyes for 3 yrs, I would start by asking for a test for IgG antibodies to the enzyme called ADAMTS13 (good journal articles for your doctor are: http://bloodjournal.hematologylibrary.org/cgi/content/full/103/11/3997, http://malattierare.regione.veneto.it/cerca_it/dettaglio.php?lang=eng&id=1520).  The two main problems are: 1) microclots caused by the antibiotic that cause excessive shear stress on the red blood cells and 2) a drastic reduction in the amount of ADAMTS13 enzyme because the body mistakenly sees it as a foreign substance and gets rid of it. Protein function is very much regulated by shape, and my guess is that the antibiotic molecule attaches itself to the enzyme, and renders it foreign to your body. This condition is called thrombotic thrombocytopenic purpura (TTP). While the enzyme test is being done, i would ask for a full eye workup to rule out any serious eye conditions. If the antibiodies are found in abormal levels in your test results, ADAMST13 can be replaced through a plasma treatment from what I have read. Lastly, did you get your vitamin D level checked yet? A vitamin D deficiency can affect the eyes as there are vitamin D recptors all over the eye, particularly the retina.