nur surah 30 explanation, believers shall subdue their eyes? protection for eyes

dual

nur surah 30.
Tell the believing men that they shall subdue their eyes (and not stare at the women), and to maintain their chastity. This is purer for them. GOD is fully Cognizant of everything they do.
this surah encourages believers to look down while walking to avoid staring at females. interestingly, looking down may be helpful advice for our eyes.

Looking at the floor may reduce eye strain in some situations because it can help to reduce the amount of glare and bright light that enters your eyes. For example, if you are walking outside on a sunny day, looking at the ground may reduce the amount of direct sunlight that enters your eyes and causes discomfort.

the limitation is that it is unclear whether this verse means believers should look down while walking in the street.
God knows better.

dual

also, same surah mentions blindness in the verse 61.