The Eye - Medical Conditions [back]
Floaters and Flashing Lights

The vitreous is a clear jelly that fills the middle of the eye, lying against the retina. In a newborn, the vitreous is quite thick and attached to the retina. With increasing age, the vitreous becomes more liquid and shrinks away from the retina. This process is known as a posterior vitreous detachment (PVD). This sometimes happens earlier in those who are short sighted (myopic) or those who are diabetic. A PVD can occur suddenly or over a number of days.

PVDs can happen without any symptoms at all and without damaging the retina. In some cases, the vitreous can pull on the retina as it detaches, causing you to see tiny flashes of light, especially in the dark. Clumps of vitreous can float in the vitreous space, giving rise to the appearance of floaters.

People often describe these as seeing ‘tadpoles’, ‘hairs’ or ‘cobwebs’ in their vision. Very occasionally, the vitreous may pull on the retina and cause a hole or tear, leading to a retinal detachment.

A retinal detachment is a serious condition and requires prompt medical attention. Therefore, people experiencing an onset of floaters or flashing lights should have an eye examination to detect any holes or tears in the retina. To examine the retina in detail, the pupils are dilated with eye drops, which blur the vision for a few hours.

Warning signs of a retinal detachment following a PVD are:

• An increase in flashes or floaters.

• A curtain like effect in the vision or an area of vision missing.

If you experience any of the above, you should seek medical advice as soon as possible.

No treatment is necessary for a PVD if the retina is healthy. The floaters usually subside by themselves, although larger floaters may be noticed for longer. Most people learn to live with the floaters and the brain often ignores that they are there.