What is one of the signs of CNS O2 toxicity?

Tinnitus in the ears is a recognized sign of central nervous system oxygen toxicity. This condition occurs when a diver breathes excessive oxygen under high pressure, leading to the formation of reactive oxygen species which can affect the brain and the auditory system. The onset of symptoms such as tinnitus typically indicates that the diver is experiencing neurological effects due to elevated oxygen levels, which may precede more severe symptoms like seizures or altered mental status.

Understanding CNS oxygen toxicity is critical for divers as it can have serious implications during deep dives or when using high ratios of oxygen. Recognizing early signs such as tinnitus helps in preventing further complications by allowing the diver to ascend to a safer depth or take other corrective actions.