Age-related changes in the vitreous: The vitreous body is gel-like at birth, and signs of liquefaction begin to appear within the vitreous body at the age of 4 years. Liquefaction refers to the gradual dehydration and contraction of the gel-like vitreous body and the separation of water from collagen. at 14-18 years of age, 20% of the vitreous cavity is liquid. at 45-50 years of age, there is a significant increase in the water component of the vitreous body, along with a decrease in the gel-like component. at 80-90 years of age, more than 50% of the vitreous body is liquefied. Further liquefaction of the vitreous in the elderly leads to vitreous detachment. The separation of the vitreous and lens capsule is called anterior vitreous detachment; the separation of the vitreous and the inner retinal boundary membrane is called posterior vitreous detachment, with an incidence of about 58% in people over 50 years of age and 65% to 75% in people over 65 years of age.