Aging is accompanied by significant physical and biochemical changes in the vitreous. The most important changes are syneresis and ablation of the posterior vitreous.
Syneresis is vitreous liquefaction, possibly caused by the disappearance of hyaluronic acid.

Ablation of the posterior vitreous membrane patient notes as a dark circle or the letter C in the part of the visual field. It can cause divisions in the retina with consequent bleeding in the retina and / or vitreous or even ablation of the retina.

Enthopsia (“flies”) – seeing floating spots like tiny flies, caused by floating gentle blurs (small groups of hyalocytes) in the vitreous, are a normal and frequent condition, more common in susceptible people. They should be distinguished from the sharply made dark circles, large spots, veils, fixed blurs and shadows that suggest a serious illness of the vitreous, retina or choroid: ablation or rupture of the retina, ablation of the vitreous, bleeding into the vitreous or chorioretinitis.