i have slight red eyes on my left last september 2013, my optalmologist prescribed an eyedrop antibiotic the redness slightly disappear , but the redness re appear after a few days , then he prescribed another eye drop prednisolone, but it is not effective until i experience eye pain , then he prescribed flarex which he says i will take for 8 days , the redness slighly disappear in my left eye but i still feel pain on my left eyebrow i feel this during night , when i apply a liniment and a warm compress it can make the pain slightly disappear . what could be the cause of this pain ?