My mother has hardly any baby pictures of me, and when I once asked her why, she waved her hand vaguely and said I looked funny. Opening a shoebox, she pulled out a handful of small black-and-white photos with pinked edges. There I was, wispy-haired and dimple-kneed, your basic baby, except for the eyes. My eyes turned inward, especially the right one, as if trying to focus on a spot on the bridge of my nose. Or maybe as if they weren’t ready to see what was out there.

I had known, of course, that I was born with crossed eyes. Because of my crooked eyes, I not only look different, I see differently. And there are some things I don’t see at all. This dusty box of old photos was another reminder of what has been hidden from me.

About two percent of newborns have strabismus, meaning one or both eyes aren’t aligned. The muscles that control eye movement and position are imbalanced, so the eyes can’t focus straight ahead. Most strabismic children are born with inward turning eyes, also called esotropia. This is a problem.

Normal vision is “binocular” —both eyes focus on an object or scene, and each eye takes a two-dimensional picture from its perspective. Because of the spacing of your eyes, each picture is taken from a slightly different angle. The brain fuses the two images to create an image that, when interpreted by the brain, seems three dimensional. This fusion, known as stereopsis, creates depth perception.

With strabismus, both eyes take a picture, but because the pupils are off center, so are the images, and the brain can’t fuse them. This means that the brain “sees” two separate images. To avoid seeing double, my brain learned to suppress the picture from the more inward turning right eye.

When I was about a year old, the doctor had my parents put a patch over my left eye. The idea was to strengthen and straighten my right eye by forcing it to work on its own. It wasn’t a cute little pirate patch, but a big Band-aid colored one, secured to my forehead and cheek by a couple strips of white tape. (There aren’t many photos from that time either.) The patching didn’t succeed, so a year later I had surgery. My left eye straightened out pretty well, but the right one shifted from its inward gaze to a position slightly upward and to the right of center.

Without straight eyes, and despite many years of eye exercises as a child to force my right eye to cooperate, I never developed binocular vision. My brain continued to pay attention only to the image from my stronger left eye. I say stronger because it was straighter, but in fact, without glasses, my left eye was about 20/1000. My extreme nearsightedness was made worse by astigmatism—blurriness caused by an asymmetrical cornea. Even with glasses, the vision in my left eye is not very sharp.

* * *

It’s the first dance with the boys’ camp and I want to be pretty. I am twelve, with slim tanned legs and long straight hair, but all I see in the mirror are brown, thick, cat-eye glasses. So tonight I leave my glasses in the cabin and blindly follow the other girls into the dining hall decorated with crepe paper and lanterns. The boys stand awkwardly on one side of the room and the girls on the other. Now a boy is walking toward me—I think—or is he headed toward another girl? He passes her and comes right up to me and asks where I’m from. Up close I can see he’s really cute, with tousled brown hair and spirited eyes. Emboldened, his buddies cross the divide and crowd around me. I am in the center of a group of eager boys. The cute boy asks me to dance, Jim Morrison is singing “Come on baby light my fire,” the room is a blur except for the boy now looking into my eyes. I am Cinderella at the ball: when it is over, I will be able to see again, but he will ignore the girl in the cat-eye glasses.

* * *

Although my right eye sees remarkably better than the left (20/50), my left eye still does all the work. I think of my right eye as a passive participant in my vision; it registers what’s on the right side, but if I want to actually look at something on the right I turn my head so my left eye can interpret it. If I close my left eye, the right eye sees pretty well, but it moves slowly, tires quickly and reads at about the pace of a second grader. Eye doctors never bother to give me a corrective lens for my right eye, because it doesn’t matter.

What I see can perhaps be described as what others see when viewing a movie or photograph. But while my brain can’t perceive depth the way most people’s brains do, I do have some depth perception. My brain (everyone’s brain) uses many cues to judge depth, such as how fast objects move in relation to other objects or how they shift as I move my head. The scientific terms that describe monocular depth perception cues are evocative: kinetic, parallax, distance fog, converging at infinity. The words almost seduce me into thinking these tricks create for me a fully three-dimensional world. In fact, some scientists and doctors believe that people with my type of vision—monocular, one eyed—are only at a disadvantage when seeing things close up.

* * *

Mrs. Powell, my sewing teacher, frowns at me. I lick the end of the kelly green thread and try again. I hold the needle close to my face and slowly bring the thread toward the sliver of light at the needle’s eye; my eyes burn from the effort of focusing. The thread brushes past the needle like strangers passing on a narrow sidewalk. The other girls are sewing rickrack onto their aprons with tidy little stitches but I haven’t started because my needle and thread are in two dimensions and the needle is like a reflection, never exactly where I expect it to be.

* * *

I have always wondered about what normal people see. Take stereoscopes. When I look through one at, say, a photograph of the Eiffel Tower, I see it with my left eye, and I think it looks just like the real Eiffel Tower. When others look through the stereoscope first with one eye, and then with their two normal eyes, they say the Eiffel Tower is suddenly three-dimensional, poised in the space around it, real in a way that a two-dimensional photograph is not. Real is also the word my husband used when we saw a 3-D movie recently. To me, it looked like any other movie. So if the three-dimensional world is real, does that make my world unreal?

A few years ago I read an article suggesting an answer to that question. It was about a woman with strabismus and monovision. She had a type of strabismus in which neither eye is dominant; instead, the brain shifts rapidly between the image from the left eye and the one from the right. She began intensive vision therapy to train her eyes to work together; within weeks she achieved stereovision. Her descriptions of what she sees now versus what she saw with monovision are like the difference between seeing the world in color instead of shades of grey. Objects stick out in space, everything is more textured, sharp, colorful, nuanced. When she goes for a walk, each flower, each leaf she sees seems to stand out by itself. When it snows, she feels as if she is among the snowflakes instead of looking at a flat plane of falling snow.

Vision therapy won’t work for me because my right eye can never be strong enough to get my brain’s full attention: I will never walk inside that snow globe. Reading that article was like reading a travelogue from someone visiting a beautiful country I know I’ll never get to see. It’s a land of stunning vistas, glorious colors, gorgeous sights — but my passport is no good there. For the first time, I understood the enormousness of what I was missing.