Millions of households rely on their dishwashers to tackle the daily mountain of dirty dishes, saving time and effort at the end of a busy day.

But if you’re in the habit of putting your glasses in with everything else, you might be setting yourself up for a costly surprise.

Dishwashers are convenient but not always gentle, especially when it comes to glassware.

The combination of high temperatures, powerful jets of water and harsh detergents can gradually damage even good-quality glasses.

Over time, this can leave them looking cloudy, scratched or, worse still, cracked and ready to break.

One common issue is the cloudy film that appears on glass after repeated washes.

Many people assume it’s just water spots, but in reality, it’s often tiny scratches etched into the surface by strong detergents and abrasive particles.

Unlike smudges or fingerprints, this haze doesn’t come off with a quick polish — once it’s there, it’s usually permanent.

Another risk is chipping or breakage. Glasses can knock together during the wash cycle or get knocked against harder items like saucepans or cutlery.

This is especially true for delicate wine glasses and thin tumblers, which can become brittle when exposed to extreme heat.

Replacing broken or damaged glassware isn’t cheap — and it’s avoidable with a few small changes to your washing routine.

To protect your glasses and keep them sparkling, experts recommend a few simple tips:

• Hand-wash delicate or expensive glasses with warm soapy water instead of putting them in the dishwasher.

• If you do use the dishwasher, always place glasses on the top rack, where the water pressure is gentler.

• Keep glasses away from heavier items that might knock into them during the wash.

• Choose a gentle or ‘glass care’ cycle if your machine has one, and avoid high heat settings.

• Add a rinse aid to help prevent spotting and streaks.

• For tough spots, a splash of white vinegar can help bring back shine without scratching the surface.

Next time you’re tempted to toss your glasses in with the dinner plates, take a moment to think twice.

Spending an extra couple of minutes washing by hand could save you money in replacements — and keep your cupboard stocked with crystal-clear glassware for years to come.