The process of undergoing sex reassignment surgery is extensive and rather arduous. People who so much as question their sexuality are encouraged to see a psychologist, and they are usually recommended to undergo sex reassignment surgery in order to fit in with the strict gender binary that is present in Iran. The individual goes through four to six months of therapy, hormone tests, and chromosomal tests to undergo a process known as "filtering". Filtering is the separation of homosexuals, who are deemed "deviant", from transsexuals, who are deemed "curable" by undergoing surgery. Once a transgender individual has undergone sex reassignment, that person legally becomes the new sex. All legal documents, such as birth certificates and passports, are also changed accordingly.