A. Yusuf Ali:Translation:
Say to the believing men that they should lower their
gaze and guard 2983 their modesty: that will make
for greater purity for them: And Allah is well
acquainted with all that they do.

Muhammad Asad:Translation:
Tell the believing men to lower their gaze and to be mindful of their chastity: 36 this will be most conducive to their purity – [and,] verily, God is aware of all that they do.
2983 The rule of modesty applies to men as well as women. A brazen stare by a man at a woman (or even at a man) is a breach of refined manners. Where sex is concerned, modesty is not only "good form": it is not only to guard the weaker sex, but also to guard the spiritual good of the stronger sex.