Yes, the most common thing that would cause that is a vitreous floater. Follow the like helpfully posted by Jim123456 Although most are harmless if you have not had a MD ophthalmologist check you eyes in the last 12 months make an appointment to have them checked. Find one at www.aao.org
JCH III MD
I'm not an eye doctor, but it sounds like you have a somewhat normal eye condition called "eye floaters." I've had them my whole life, as well. They can vary in size or color, but are usually either round or worm-like, and can be pale or black. You can find more information on this link:
http://www.mayoclinic.com/health/eye-floaters/DS01036