Flashes and Floaters
The eye is like a complex ball. The back 2/3rds of this ball are filled with a gel-like tissue called the vitreous. The vitreous has the consistency of solid gelatin at birth and is important for the normal maturation and development of the eye. After age 4 or 5, the eye matures to its adult size and the vitreous begins a long process of degeneration and become more liquid (liquefaction) and less gel-like in in consistency. As this occurs, the vitreous begins to contract and will eventually separate away from the retina. This event is called a posterior vitreous detachment (PVD). When this happens, people suddenly see parts of the vitreous as spots, webs, rings, or opacities in their vision. We call these floaters and they move with eye movement and will usually become less bothersome with time. This is a normal process and, while annoying at first, the floaters do get better most often. Sometimes, floaters can persist and surgery (vitrectomy) can be considered.
When a PVD occurs, the peripheral gel is still solid and attached firmly to the edge of the retina. When the gel pulls, it can causing streaks of flashing lights in the peripheral visual field. People usually see these in a dimly lit room or at night. If the vitreous pulls too hard, a tear in the retina can occur. A tear in the retina may be associated with hundreds or thousands of tiny, dot-like floaters. A retinal tear can quickly lead to a retinal detachment and so prompt evaluation is warranted for flashes and floater. Retinal tears can be treated in the clinic with laser or cryotherapy (freezing treatment) to decrease the risk of retinal detachment.