Exegesis:

ei oun to sōma sou holon phōteinon ‘if then your whole body (is) bright,’ taking up the first conclusion of v. 34.

mē echon meros ti skoteinon ‘having no dark part,’ elaborating holon.

estai phōteinon holon ‘it will be wholly bright,’ best understood as determined by what follows, i.e. the reference to a light from outside: when the light from the inside is in order, then the body will enjoy also the light from the outside.

hōs hotan ho luchnos tē astrapē phōtizē se ‘as when the lamp illuminates you by its light.’

astrapē here ‘light,’ ‘brilliance’ (cf. 10.18).

phōtizō ‘to illuminate.’

Translation:

Having no part dark, or, ‘there-is not a bit in it dark’ (Bahasa Indonesia RC).

A lamp with its rays gives you light, or, ‘the rays/light of the lamp illuminate(s) you, or, cause(s) you to be bright,’ or simply, ‘the lamp shines on you.’

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.