The command to destroy the eye, perhaps the most important part of the body, is probably an exaggeration for his hearers to do anything necessary to remove from their lives anything that causes them to sin. (See: [[rc://en/ta/man/translate/figs-hyperbole]])
All occurrences of these words are singular. Jesus is speaking to all people in general. It may be more natural for your language to translate with a plural "you." (See: [[rc://en/ta/man/translate/figs-you]])
# into life
"into eternal life"
# than to be thrown into the eternal fire having both eyes
This can be stated in active form. Alternate translation: "than to have both eyes when God throws you into the eternal fire" (See: [[rc://en/ta/man/translate/figs-activepassive]])