Flashes occur when the vitreous gel pulls on the retina, and you may see what look like flashing lights or lightning streaks. It is more common to experience flashes and floaters as we grow older because the vitreous gel changes with age, gradually pulling away from the inside surface of the eye.
Floaters are small specks that move in and out of your field of vision. They may be more noticeable when looking at a plain background. Floaters are tiny clumps of cells inside the vitreous humour (the clear fluid that fills the inside of the eye) that can be different shapes.