The most commmon cause for seeing spots is condensation of the gel that fills the inside of your eyeball. As the gel condenses, a normal development over time, the little
fibres within it separate out and float in the gel. As light passes through your pupil at the front of your eye and through the gel filling your eyeball on its way to your retina in the back of your eye, the little fibres cast shadows on the retina and you see these as spots. They are commonly called "floaters" because they appear to float in your vision and are usually more apparent against a light background. If this description does not describe your experience or if you are seeing flashes of light in addition to the spots or if you have pain, acute light sensitivity or decreased vision in the affected eye, you should see an ophthalmologist.