The honest answer is that you cannot remove a scratch from a lens. A scratch is missing material, and nothing sold in a bottle puts material back. Everything marketed as scratch repair either fills the groove or grinds the surrounding surface down to meet it, and on a coated lens both make the problem larger.
That is worth knowing before you spend money, because the remedies are where most of the damage happens.
Why the popular fixes fail
Toothpaste. A mild abrasive. On an uncoated lens it may dull a shallow scratch by dulling everything around it. On a coated lens it removes coating in a patch, which is far more visible than the original mark and catches every light source at night.
Baking soda paste. The same mechanism, coarser.
Brass or metal polish. Abrasive compounds designed for metal. They will take coatings off completely and haze the plastic underneath.
Commercial scratch-repair kits. These usually deposit a filler into the groove. It reduces the visible line briefly, then clouds, yellows, and collects grime at the edges. It also has to be removed before a lens can be professionally assessed.
Car headlight restoration compounds. Formulated for thick polycarbonate headlamp covers with no optical requirement. A lens you look through is not the same object.
Work out what you are actually looking at
Clean the lens properly first – rinse, a drop of lotion-free dish soap, rinse, blot dry. A surprising proportion of scratches are dried residue, cosmetic film, or a smear that survived a dry wipe.
Then hold the lens at an angle to a light and decide which of three things you have:
- A single line, catching light. A true scratch. Permanent.
- A haze of fine arcs. Cumulative dry-wiping damage. Also permanent, and the more common failure.
- A crazed web, or a patch with a rainbow sheen. Coating failure rather than a scratch, usually from heat or a chemical. Cannot be polished out at all.
Does it matter where it is?
Enormously. Your eye ignores damage outside the central viewing zone within a few days.
Hold the frames up and look through them normally. A scratch near the rim will not trouble you. One sitting where you look through most of the time will keep drawing your eye, and will scatter light at night regardless of how fine it is.
That single test decides whether this is a live-with-it problem or a replace-the-lenses problem.
The real options
Live with it. For peripheral marks, genuinely the right answer.
Replace the lenses. Most quality frames can be re-lensed, either through the manufacturer or an independent service. If the frame is mechanically sound – firm hinges, no cracks, sits flat – this is replacing the consumable part of a durable object, which is what a serviceable frame is for.
Claim, if it is coating failure. Delamination and crazing that appeared without impact may be a manufacturing defect rather than wear. Within the warranty period, with proof of purchase from an authorised seller, it is worth presenting.
Replace the pair if the frame needs work too. Putting new lenses into a frame with hinge play means paying twice.
Preventing the next one
Most lens damage is not dramatic. It is a few hundred small events a year.
- Rinse before touching a lens. Airborne dust is largely silica, harder than any coating. Dry-wiping grinds it across the surface.
- Never a shirt hem, tissue or paper towel. All abrasive at coating scale.
- Set them down folded, lenses up. Never face-down, not even briefly.
- Hard case in a bag. A pouch stops scratches and nothing else.
- Wash the microfiber monthly, without fabric softener. A cloth full of trapped grit is a polishing pad.
None of that recovers a lens you have already scratched. It is the whole of what keeps the next pair clear, which – given that the only real repair is replacement – is where the effort belongs.