In general, if the noun is used in the feminine (the lens), one speaks of the optical glass, while when using it in the masculine -and plural (the lenses), one speaks of the devices that serve as an aid in vision problems, also called glasses.
|Explanation||Also called positive lenses. When light passes through this type of lens, it converges (joins) at a certain point.||As for the divergent, or negative, these cause the light rays that pass through them to separate or diverge.|
|Characteristics||Converging lenses are thick in the center and get progressively narrower towards the edges.||Unlike converging lenses, diverging lenses are thick at the edges and this thickness progressively decreases as it approaches the center.|
|Types||Converging lenses can be:
||As for diverging lenses, these can be:
|Medical prescription lenses||Glasses are the most traditional way to correct vision problems. Converging lenses are especially useful for treating problems such as farsightedness, eyestrain, and astigmatism.||As for the concave type lenses or glasses, these are used almost exclusively in the treatment of myopia.|