I have been to the Saint Sofia medical center in Bourgas and can recomend it. They have some English speaking staff and provide a member of staff to translate for you when necessary. They have departments for all types of medical examination and treatments including an optician and a dentist. You do not have to make an appointment you can just walk in and see if it is possible to see the appropriate medical practitioner whilst you are in Burgas. Their website address is www.saintsofia.com and they can be found at 8000 Bourgas, 13 "Vazrajdane" str.
(behind Sptemvri cinema)