This black fleck is called a vitreous
floater. Floaters are a common occurence and are not dangerous. They occur due to a normal degeneration of the vitreous, the jelly that fills the eye. As we get older, the vitreous goes from jelly to a more liquified constency. The collagen that makes up the vitreous begins to collapse on to itself forming the sort of flecks that you are seeing. Actually, what you see is the shadow of the floater being cast on to the back of the eye (the retina). This is the reason it is more evident in bright light.
As part of the process, the vitreous also becomes separated from the retina. Sometimes, the vitreous is very adherent to the retina and can create a tear that puts the patient at risk of a retinal detachment
. Often, as this occurs, the patient will see flashing lights at the periphery of the vision. This is a reason to visit an ophthalmologist
sooner rather than later.
If you are not seeing flashing lights, I would not consider this an emergency. However, I would suggest a visit to an ophthalmologist at your earliest convenience for a complete eye exam. Unfortunately, there is no treatment for floaters, but in time they are less noticeable.
I hope this is helpful...