Lichtzwang (rendered in English as Lightduress) is a 1970 German-language poetry collection by Paul Celan.

The book was published in Germany in 1970 through Suhrkamp Verlag.

Joris won the American PEN Award for Poetry in Translation for the book; the motivation said that "The translations are consistently alert to the subtle and often bewildering thought-turns of the original, his lyric sense of pause, suspension and onrush can keep pace with the German, and his vast knowledge of Celan's life and world allow vital commentary and annotations.

"[1] Mark Glanville reviewed the book in Jewish Quarterly in 2005: "In the terse economy of Lichtzwang language has become as constricted as the divine light captured in the kabbalistic kelippot (shells) that Celan alludes to elsewhere, and to which the title of this collection might well refer.

We are aware of the poet's battle against the dying of the light, one he eventually lost, but the quality and nature of the struggle is such as to leave us with a body of work by which we continue to be illuminated and inspired.