Matthew 6:23

but, if your eye be evil, your whole body will be dark. If, therefore, the light that is in you be darkness, how great the darkness!

Luke 11:34-35

The lamp of your body is your eye. When your eye is sound, your whole body also is full of light; but, when it is evil, your body also is dark.

Ephesians 5:8

for ye were once darkness, but now are ye light in the Lord; walk as children of light

Treasury of Scripture Knowledge

Summary

Then I saw that wisdom excelleth folly, as far as light excelleth darkness.

Bible References

Light

Matthew 6:23
but, if your eye be evil, your whole body will be dark. If, therefore, the light that is in you be darkness, how great the darkness!
Luke 11:34
The lamp of your body is your eye. When your eye is sound, your whole body also is full of light; but, when it is evil, your body also is dark.
Ephesians 5:8
for ye were once darkness, but now are ye light in the Lord; walk as children of light