What are the effects of oxygen toxicity in human blood?
This is from a Wikipedia article:

Central nervous system oxygen toxicity manifests as symptoms such as visual changes (especially tunnel vision), ringing in the ears (tinnitus), nausea, twitching (especially of the face), behavioural changes (irritability, anxiety, confusion), and dizziness.
Oxygen toxicity - Wikipedia
https://en.wikipedia.org/wiki/Oxygen_toxicity

It says there's hemolysis of red blood cells - i.e., they lyse = break open.