On the way out to a offshore oil platform the other captain let me borrow his sunglasses. When I put them on I could see these blue lines in all wheelhouse windows. Was wondering what causes this effect.
Stress lines in the glass, probably part of the protection against shattering. They are there all the time but more prominent when viewed in polarized light. If you looked through them and rotated the lens you would see the pattern change.
Polarized sunglass lenses reduce light glare and eyestrain. Because of this, they improve vision and safety in the sun. When working or playing outdoors, you can become frustrated and even temporarily blinded by reflected light and glare