Which type of contact lens has 60% water content and is prone to deposits?

The correct choice is that high water ionic contact lenses, which fall under group 4, are known for their high water content of around 60%. This characteristic makes them more prone to the accumulation of deposits, such as proteins and lipids, because the higher water content can facilitate the interaction of the lens surface with these materials.

High water ionic lenses have a hydrophilic composition, which enhances comfort and oxygen permeability but also makes them susceptible to these deposits. Proper care and cleaning are essential to maintain lens clarity and comfort when using this type of lens.

In contrast, low water non-ionic lenses are designed to have a low water content, which inherently reduces the ability of these lenses to attract and hold onto deposits. Silicone hydrogel lenses, while supportive of oxygen transmission, do not have the same water content characteristics and manage deposits differently. Medium water ionic (group 3) lenses have a different combination of water content and ionic properties, which also influences their deposit susceptibility but not in the same manner as high water ionic lenses.