Passwords help people avoid unauthorized access to their personal devices but are not without challenges, like memorability and shoulder surfing attacks. Little is known about how people with vision impairment assure their digital security in mobile contexts. We conducted an online survey with 325 people who are blind or have low vision and found they are concerned about entering passwords in public because of the risk of others observing their passwords. We also found PINs, commonly required on smartphones, are considered insecure and poorly accessible. To solve those issues, we investigated the usability of bend passwords, a recently proposed method for authentication that uses a combination of pre-defined bend gestures performed on a flexible device. We designed a new deformable prototype and ran a user study with 16 vision-impaired participants, finding that bend passwords are as easy to learn and memorize as PINs, but are faster to enter than PINs.