While many of us note the occasional floater, the presence of new floaters or flashes of light may signal a sight threatening event. Floaters and flashes are caused by the vitreous gel that fills the eye and lies against the retina. Normal floaters are caused by vitreous degeneration. As we age, the vitreous gel begins to degenerate into clumps of proteinaceous material which float in the eye. With time, the gel will separate from the retina. As the gel separates, it may pull on the retina. The mechanical traction on the surface of the retina will stimulate the underlying photoreceptors and lead to the perception of light flashes. In some cases, the pulling may cause a retinal tear and/or a blood vessel may tear leading to severe loss of vision.
A patient with new floaters or flashes should be examined promptly since these signs may indicate a retinal tear. With early diagnosis the tear may be treated with laser surgery or a freezing therapy termed cryotherapy. This will significantly reduce the chance of the tear progressing to a retinal detachment.