What is crazing on lenses and how to avoid it

What are these circular lines through my lenses? (They're not scratches and are pretty prominent in bright light, but aren't visible otherwise. Glasses are four years old.) : r/glasses

CROSSING THE FINISH LINE WITH AR LENSES

Crazed Lenses, Blog

Why your glasses are crooked

How to avoid germs on your eyeglasses - All About Vision

Self-Darkening-Eyeglasses, 44% OFF

Strange lens defect?

What are these clusters of branching structures on/in my lens? - Photography Stack Exchange

Peace of Mind from Lens Crazing

ANTI GLARE GLASSES WATCH BEFORE YOU BUY: 16 INSIDER TIPS on Anti reflection coatings eye glasses

Impossible to Clean Smudge

What are these clusters of branching structures on/in my lens? - Photography Stack Exchange

Anti-reflective Coating: Guide to Solve Glare Problem on your Product - Wee Tect

Lenses Under Pressure: The Real Story of Stress Fractures