Floaters are small specks or strands that move through a person’s field of vision. They are often most visible when looking at a lighter background such as a lightly colored wall, piece of white paper, or the sky. Floaters are small clumps of gel or cells that move around in the vitreous, the gel that fills the middle of the eye. Floaters can sometime look like cobwebs, circles, lines or dots.
Floaters can be caused by many things. Most of the time, floaters are caused by the vitreous gel in the eye thickening and shrinking as the eye ages, causing little clumps to form. If the vitreous gel pulls away from its attachments to the retina, called a posterior vitreous attachment, it can clump up and make a larger floater.
Floaters can also be caused by other changes in the eye. The retina is the tissue that lines the back of the eye that contains the photoreceptor nerve cells that transfers images to the brain. Sometimes tears in the retina can occur, releasing cells into the middle of the eye that appear as many small floaters. Inflammation in the eye can also cause floaters to appear in the vision. Retinal tears or inflammation in the eye can lead to vision loss.
Flashes, as the name suggests, appear as sudden flashes of light or "lightning streaks." When the vitreous gel rubs or pulls on the retina, it causes a flash of light in the vision. Flashes can occur when there has been a tear in the retina or when a retina detachment is occurring. Flashes can also be caused by other conditions like migraines.
If you notice a sudden appearance of increased floaters and/or flashing lights in your eye, you should see ophthalmologist immediately. This could indicate a retinal tear, a retina detachment, or another eye problem has occurred that could be a vision-threatening condition.