What are some examples of surface defects in spectacle lenses?

Surface defects in spectacle lenses can include:

- Scratches: These can be caused by cleaning lenses with abrasive materials, such as rough cloths, or by mishandling the lenses.

- Chips: These are small pieces of glass that have been chipped off the edge of the lens. They can be caused by dropping the lenses or by hitting them against a hard surface.

- Cracks: These are small cracks in the glass of the lens. They can be caused by high temperatures, sudden temperature changes, or by dropping the lenses.

- Pits: These are small, shallow depressions in the surface of the lens. They can be caused by manufacturing defects or by wear and tear.

- Bubbles: These are small air pockets that are trapped in the glass of the lens. They can be caused by manufacturing defects or by damage to the lens.

- Warpage: This is a distortion in the shape of the lens. It can be caused by high temperatures, sudden temperature changes, or by incorrect storage.