This lecture introduces cryosurgery for optometric surgeons, focusing on cryobiologic principles and mechanical factors that enable predictable tissue destruction. Participants will explore mechanisms of cryo-induced cellular injury and death, the impact of cooling rates, freeze times, and thawing dynamics, and how equipment choice and technique influence outcomes. The session provides a scientific and technical foundation for the safe, effective, and reproducible use of cryosurgical procedures in periocular and adnexal disease management.