When Dad Saw Double

When my father was in his early eighties, he decided to quit driving. I was tremendously relieved and assumed his lifestyle would not change radically. He did not need to drive much—just a few trips to the grocery store and to lumber and art stores where he bought the wood, canvas, and paints to make his oil paintings. I could take him to those destinations. His way of life should stay the same.

But over the next couple of years, my father’s world contracted dramatically. He barely left his house; I had to beg him to go for a short walk with me around his quiet neighborhood. He was getting increasingly withdrawn and depressed. I was at a loss to explain his behavior until I noticed that he kept squinting his left eye shut. I’ve been cross-eyed since early infancy, and I knew that a word for crossed eyes (strabismus) in Great Britain was “squint.” Could my father be squinting his left eye because it was turning in? If so, the left eye would be aimed at a different place in space than his right, providing his brain with confusing and conflicting visual input.

I thought back to a story my father had told me about his days in the Air Force during World War II. Since he was an artist, he had been assigned to interpret aerial photographs. Sometimes, he’d be given stereo pairs of photographs which he viewed through a stereoscope. While he could see the 3D in the images, he told me that his sense of the 3D was not as good as others. Perhaps, he had always had subnormal binocular vision. When he stopped driving, he no longer needed to look in the distance. Indeed, he rarely looked further than the walls of his tiny house. Without driving, he had lost the ability to keep his eyes aligned, especially for distance viewing. Eye alignment, I concluded, was not a strong suit in our family.

So, one afternoon, during a typical visit, I sat about five feet from my dad and asked him, quite casually, how many heads did I appear to have. My father studied me for a while and then responded with great surprise: “You have two!” He could still read without the letters doubling, but when we gazed out the window, all the objects outside appeared double. He hadn’t noticed this previously, but, then again, he had avoided looking out. No wonder, my father was reluctant to take a walk with me. His perceptual world was thrown into confusion.

I took my father to my developmental optometrist who diagnosed his condition as left esotropia (left eye crossed). She fit him with a pair of glasses with prisms for distance viewing. The prisms bent the light in a way that compensated for my father’s turned eye so that the two eyes saw the same region of space. Since my dad had, for most of his life, fused images between his two eyes and seen in stereo depth, the prisms were all he needed to regain a single view of the world.

This incident made me wonder how many other elderly people suffer from double vision. Like my father, they may avoid all activities that bring out the doubling so that they are only vaguely aware of their problem. Double vision may not only impact a person’s lifestyle but may lead to serious injury. Many elderly people suffer broken bones, brain injury, or even lose their lives from falls. Shouldn’t they all receive comprehensive binocular vision exams?