en_tn/2pe/01/09.md

whoever lacks these things

any person who does not have these things

is so nearsighted that he is blind

Peter speaks of a person who does not possess these qualities as if he were a nearsighted or blind person because he does not understand their value. Alternate translation: "is like a shortsighted person who cannot see their importance" (See: rc://en/ta/man/translate/figs-metaphor)

he has been cleansed from his past sins

You can use a verb to translate this. Alternate translation: "that God has cleansed him from his old sins" (See: rc://en/ta/man/translate/figs-abstractnouns)