Styes are infection of Moll & zeis gland present in every body eye lids ,basically infected by staphylococci.styes are very painful swelling near the root of eye lashes, you need oral antibiotics&anti inflammatory tablet as well as antibiotic ointment to apply locally.Hot fomentation helps to some extent in styes.In multiple &recurrent stye you may try homeopathic medicine from good homeopath.In text books refractive error has been mentioned probable cause of recurrent stye but it is very common in emmetropic eye also.