Why should cleaners that contain isopropyl alcohol not be used on rigid lenses?

Cleaners that contain isopropyl alcohol should not be used on rigid lenses because they can lead to parameter changes, brittleness, and cracking of the lens material. Isopropyl alcohol is known to have a drying effect, which can compromise the integrity of rigid gas permeable (RGP) lenses. This can result in structural weaknesses, making the lenses more prone to damage and reducing their lifespan.

Additionally, the exposure to isopropyl alcohol may alter the physical characteristics of the lens, affecting how it fits and performs. Rigid lenses are made from specific polymers that can be altered chemically by harsh solvents. Using inappropriate cleaners can lead to issues that not only make the lenses uncomfortable but may also necessitate replacements more frequently than normal.

The other choices highlight potential issues associated with lens care, but they do not encompass the critical impact of isopropyl alcohol on the material properties of rigid lenses as effectively as the correct answer does.