Which does not handle free radicals inside lens –
Enzymatic antioxidant mechanisms :- Reduced glutathione (most important), glutathione peroxidase, superoxide dismutase, catalase.
Non-enzymatic defence mechanisms :- Vitamin C, Vitamin E, and possibly carotenoids.
Some textbooks have also mentioned vitamin A as an anti-oxidant in lens. But, the best answer here is vitamin A because all other options have been mentioned as anti-oxidants in all textbooks, while vitamin A has been mentioned only in some textbooks.
Vitamin A
Vitamin C
Vitamin E
Catalase