Monday 9 June 2008

Seeing Things? Part 1 - Floaters

Do you sometimes see grey or semi-transparent dark-edged specks, strands or squiggly lines in your field of vision, particularly if you are looking up at the clear sky or at a blank wall? As I’m writing this, I’m aware of seeing a couple against the white of my MS Word page –one is circular in shape, transparent with a dark nucleus and dark ring around its edge, while the other looks like a tiny grey worm! They are similar in appearance to the ones in the picture below.


People who experience these usually have one of two reactions: either they fear that there is something drastically wrong with their eyes or vision, or if they are interested in the paranormal, they often get excited that they are seeing energy or evidence of a spirit’s presence. The truth is much more prosaic than either of these, however.

These specks, strands or cobwebs are called floaters, otherwise known in technical medical terms as muscae volitantes, and they are a very common eye condition, particularly amongst middle-aged or nearsighted people. They develop when the vitreous gel, the clear jelly-like substance that fills the back two-thirds of our eye, undergoes very natural changes as we age – small pockets of liquid form within the vitreous, the strands of collagen within the vitreous become thicker and denser, and the vitreous shrinks and detaches from the back of the eye. The shapes that we see are actually the shadows cast by these liquid pockets or collagen strands floating in the vitreous as light travels through the vitreous to the retina. Because the floaters are in our eyes, they move with our eyes, either drifting across our vision or darting away as we try to focus on them directly.

Although the changes mentioned above may sound worrying, there is usually no cause for concern and they generally don’t affect vision beyond being mildly annoying. Our brains can adapt to the floaters’ presence and will learn to ignore them for the most part. Floaters also tend to decrease in size or darkness over time, or “settle” at the bottom of our eyes below our line of sight. However, if you experience a sudden increase in the number of floaters that you can see, or if your floaters change significantly, it is recommended that you visit an eye care professional, such as an optometrist or opthalmologist, so that they can check the health of your retina.

[Image credit: Acdx on Wikimedia Commons]

This is Part 1 of 5 in a series exploring common visual experiences often mistaken for paranormal occurrences. The other posts in the series are as follows:
* Part 2 - Flashes Of Light
* Part 3 - Pareidolia
* Part 4 - Retinal Fatigue & Afterimages

* Part 5 - Reflections & Conclusions

7 comments:

desperateblogger said...

dang! and i thought i was seeing visions of the unknown!

Anonymous said...

ooooh, I never thought about them being paranormal! I just had a visit to my doctor last week because of floaters. He assured me as you did - nothing to worry about.

Anonymous said...

Desperateblogger - Hehe :) Sorry to disappoint!

Journeyer - Me neither! But after reading quite a few forum posts asking whether these were evidence of the paranormal, I decided to do a post on them (which has now turned into a series on common eye conditions that people often connect to the paranormal!).

Anonymous said...

Cool... I have these sometimes and I forgot to ask my optometrist about them.

Now I don't have to worry!

Thanks. :)

Paul

Anonymous said...

Paul - It's a pleasure!

Anonymous said...

Hey, thanks for posting this blog. It was the photo that caught my attention. I always wondered what the heck those floaters were.

Anonymous said...

Hi Amy - Glad I could help!