What substance decreases in the lens with age that may affect its clarity?

As individuals age, the levels of glutathione in the lens decrease. Glutathione is a crucial antioxidant that helps maintain the transparency and clarity of the lens by protecting it from oxidative stress and damage. It plays a significant role in preventing the formation of cataracts, as it helps to neutralize harmful free radicals that can cloud the lens.

With decreased levels of glutathione, the lens becomes more susceptible to oxidative damage, leading to a higher risk of opacification and reduced clarity. This contributes to the development of age-related cataracts, which is a common vision impairment in older adults.

While substances such as ascorbic acid, sorbitol, and collagen also have roles in lens physiology, they do not have the same direct correlation to lens clarity as glutathione. Ascorbic acid is an antioxidant as well, but it is not as intimately involved in lens clarity as glutathione. Sorbitol is a product of glucose metabolism in the lens and can accumulate in conditions like diabetes but doesn’t specifically relate to age-induced changes in clarity. Collagen provides structural support but is less directly associated with the clarity of the lens as opposed to the role that glutathione plays in maintaining its transparency.