Acanthamoeba is a genus of free-living amoebae found in various environments, including soil, freshwater, and even tap water. These single-celled organisms are known for their ability to survive in harsh conditions, such as extreme temperatures and high salinity. They can exist in two forms: a trophozoite, which is the active feeding stage, and a cyst, which is a dormant form that can withstand unfavorable conditions. Acanthamoeba is significant in medical research because it can cause infections in humans, particularly in the eyes, leading to a condition known as Acanthamoeba keratitis. This infection is often associated with contact lens use and can result in severe pain and vision loss if not treated promptly. Understanding Acanthamoeba is crucial for preventing and managing these infections.