The vitreous is a transparent gel substance filling the back of the eye ball.  With age, the vitreous gel shrinks and separates itself from part of the retina.
 

Signs and Symptoms

You may notice black ‘floaters’ in your vision which move with the eye and then settle as the eye rests.  You may also be aware of flashing lights, like little flickers in the periphery.  To look at, the eye will appear normal.
 

Treatment and Diagnosis

There is no treatment required for posterior vitreous detachment.
The floaters will gradually disappear but this may take some time.
The flashing lights should gradually settle down over the next few days or weeks.
 

Warning signs of a possible Retinal Detachment

• A sudden increase in the number of floaters in your vision. 
• New floaters. 
• A portion of your visual field missing 
• A curtain coming across the vision 

This may be a warning of a retinal detachment and you should see a specialist as soon as possible.