With age, or with certain diseases of the eye, the vitreous gel begins to contract. When it does so, it starts to pull away from the retina, which lines the back wall of the eye. This is called Posterior Vitreous Detachment (PVD). During this process, certain particles or “floaters” as well as flashes of light may become visible. These can be rather annoying at first, but they are not harmful. While these don’t actually go away, most people become used to them, and they are usually not very bothersome after a few months.
However, sometimes the vitreous can have an abnormal attachment to the retina, and separation of the vitreous from the retina can cause a retinal tear, a condition which may threaten sight and required urgent evaluation and treatment
For more information, visit the American Academy of Ophthalmology Eye Health resources at: https://www.aao.org/eye-health/diseases/what-is-posterior-vitreous-detachment