In this part of the metaphor, the things they saw Jesus do provided understanding just as an eye provides light for the body. Alternate translation: "Your eye is like the lamp of the body" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Here "eye" here is a metonym for vision. Alternate translation: "When your vision is good" or "when you see well" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This can be stated in active form. Alternate translation: "the light will fill your whole body" or "you will be able to see everything clearly" (See: [[rc://en/ta/man/translate/figs-activepassive]])
Here "eye" is a metonym for vision. Alternate translation: "When your vision is bad" or "when you see poorly" (See: [[rc://en/ta/man/translate/figs-metonymy]])