Seeing Shadows

Seeing Shadows

By Andrew Ellsworth, M.D.

Will the groundhog see his shadow this year? Every year on February 2, people gather in the small town of Punxsutawney in western Pennsylvania to observe the annual Groundhog Day ceremony. If the groundhog does see his shadow, he may retreat to his den and winter will last another six weeks. If he does not see his shadow, spring may arrive early.

This tradition is nearly 140 years old. Organizers claim for the sake of folklore that the original groundhog, Punxsutawney Phil is still alive today, getting his longevity from drinking the “elixir of life.” But obviously, different groundhogs have been used through the years. The average lifespan of groundhog is only two or three years in the wild, and up to fourteen years in captivity. And besides, it’s inevitable that the groundhog’s eyesight would become less dependable as years go by. But I digress.


Like Punxsutawney Phil, some of us humans often see shadows in our vision. Eye floaters can be spots or shadows in our vision from a variety of causes. They often drift about when we move our eyes, and then dart away if we try to look at them, like a groundhog scurrying back to his burrow.

Most floaters are caused by age-related changes that occur as the vitreous, the jelly-like substance inside our eyes, becomes more liquid. Microscopic fibers within the vitreous clump up and cast tiny shadows on our retina, which we see as floaters.

Floaters are most visible when looking at a plain bright background like a white wall. They may appear as dark specks or clear strings. In general, floaters are not harmful and are nothing to worry about. However, a sudden increase in floaters may signal something worrisome, especially if you notice flashes of light or loss of peripheral vision. This may signal a retinal tear, a painless condition that requires prompt treatment to help save your vision.

As we age and the vitreous of the eye liquefies, it may sag and tug on the retina with enough force to tear it. Without treatment, the retinal tear may lead to a retinal detachment, when fluid accumulates behind the retina and separates it from the back of the eye. Untreated, this can result in permanent vision loss.

There are many reasons to go to the eye doctor once or twice per year for routine checkups to help maintain our vision. However, if you see a sudden increase in shadows, floaters, lights, or darkness of any side or sides in your vision, it’s time to leave your den and scurry back to the eye doctor regardless of the season.

Andrew Ellsworth, M.D. is part of The Prairie Doc® team of physicians and currently practices family medicine in Brookings, South Dakota. Follow The Prairie Doc® at www.prairiedoc.org and on Facebook featuring On Call with the Prairie Doc® a medical Q&A show celebrating its twentieth season of truthful, tested, and timely medical information, broadcast on SDPB and streaming live on Facebook most Thursdays at 7 p.m. central.