The vitreous humour

The vitreous humor is a gel-like substance which fills the space in the eye between the lens and the retina. It is primarily composed of water with the remainder being hyaluronic acid and collagen fibers. It is transparent which enables light to pass through while the gel form provides support to the retina and helps the eye hold its shape, essentially acting as a shock absorber. As the eye ages, the vitreous humor gel begins to lose its form and liquefy – a process referred to as synchysis. As synchysis progresses, the vitreous may separate from the retina – a condition referred to as posterior vitreous detachment (PVD). Without the stable gel form, the collagen fibers can collapse upon themselves, bind together, and become mobile. These fibers cast shadows on the retina and appear as spots and strings in the visual field referred to as floaters.

References

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