Black Spot in My Vision

When I woke up this morning I had a very prominent large black spot in my vision.  I went back to bed for a couple of hours and when I woke up it was still there.  THroughout the day it has dissappeared but I was worried that it may be something to do with Glaucoma or a Cataract.

I am only 28 but both of these conditions are in my family.. my grandparents.

I have also been worried by my mother that it could be a detached retina.  

Any ideas...should I be worried?  Is there anything else it could be like tiredness or lack of sleep? x

[Jordy3738]

Black "floaters" are pretty common as we age. They are debris (old cells) floating in the fluid of the eye. If it happens suddenly and you have a headache, you should see an opthamologist as you might have a retinal tear or worse, have detached it
http://www.surgerysurgeons.com/lasikeye.html

[John C Hagan III, MD, FACS, FAAO]

To be sure this isn't serious see an eye MD today or tomorrow. Find one at www.aoo.org

JCH MD