1. Lens Scratch Detection

Place the lens under the left lens area and observe the lens surface through a magnifying glass. Check for issues such as scratches, bubbles, delamination, uneven coating, and other problems on the lens surface.

2. Progressive Multifocal Lens Inspection

• Place the progressive lens on the grid under the middle lens area, observe through a magnifying glass, and you can differentiate the various regions of the progressive lens. The larger the grid, the higher the ADD value, as shown in the diagram below.

• After measuring the four main areas of the progressive lens in the previous step, align the distant and near areas roughly horizontally. You can find concealed markings on both sides of the lens – one side has the addition power (ADD) value (on the temporal side), while the other side does not have markings. Some brands might also have their own brand markings.

3. Lens Stress Test

• Place the lens under the right lens area, adjust the polarizing filter to an appropriate viewing angle, and observe the lens. If irregular shadows appear, there is uneven stress, and the color will be darker with higher stress. The deepest area should be polished down to reduce the stress.