When the instrument is inserted into the vagina, the two blades are separated in order to keep the anterior and posterior vaginal walls apart. In that position, the cervix and the walls of the vagina can be seen if the patient does not have an excess of loose vaginal tissue. However, in patients with excessive tissue, the sidewalls of the vagina simply collapse toward the midline between the blades because of the fact that no part of the speculum is in direct contact with the lateral walls of the vagina. This collapse prevents the complete and crucial visualization of the cervix for purposes of cervical cultures, pap smears, visual assessment of ruptured membranes, visual assessment of the degree of dilation, biopsies, and other procedures requiring access to the cervix or the uterus.