Restoration has a reputation for not lasting, and the reason is a step that gets skipped because the result already looks finished without it.

What the haze actually is

Polycarbonate lenses ship with a thin factory hard coat that degrades under UV.

Once it fails, the plastic underneath oxidises and the lens yellows and clouds.

What sanding removes

The damaged layer, and any remaining hard coat along with it.

The lens is genuinely clear at that moment, and it is also completely unprotected.

Why it hazes faster the second time

Bare polycarbonate is more vulnerable to UV than the original coated surface was.

So the same process runs again, quicker, and often within months.

The step that changes the outcome

A UV-stable clear coat applied over the freshly polished lens, quoted with a service life.

Protection film over the top extends it further and takes the stone chips.

When restoration is the wrong answer

Hazing on the inside of the lens means water or a failing internal coating.

Cracks and deep crazing cannot be sanded out. Both need replacement, not polishing.