Official English text from the Liturgy of the Hours:
O Radiant Dawn, splendor of eternal light, sun of justice: come, shine on those who dwell in darkness and the shadow of death.
Official Latin text:
O Oriens, splendor lucis aeternae, et sol iustitiae: veni, et illumina sedentes in tenebris et umbra mortis.
More literal English translation:
O dawn of the east, brightness of light eternal, and sun of justice: come, and enlighten those who sit in darkness and in the shadow of death.