Can 99.5 percent anhydrous glycerin be used to relieve dry eyes?

No, 99.5 percent anhydrous glycerin should not be used to relieve dry eyes.

While glycerin is sometimes used as a moisturizing agent in eye drops, the concentration should be much lower. Typically, glycerin is used in eye drops at a concentration of around 0.5% to 1%.

Using a concentration as high as 99.5% could cause serious irritation and damage to the eyes.