By Ethan JC Walker, PhD

Recall with me, if you will, some vistas of childhood days: Eating cereal on a lazy Saturday morning, watching the cat stretch out to stay in that brilliant yellow patch of sunlight filtering through the window; a midsummer’s day, looking up through an old oak tree, captivated by the scintillating patterns of translucent green as hundreds of leaves shift in a light breeze; a crisp fall evening, stomping through a secluded creek, each step scattering liquid diamonds, ripples blending into the chaotic, blue-white flow winding its many ways around glistening rocks. All of these vivid memories were full of color and bright lights. Returning to these places as an adult, with more patience to notice the differences, has made me wonder: was the world really brighter back then?

Maybe you have also wondered why everything felt so much brighter, so much more vibrant in old memories, compared to here and now. Even though the sun surely has not gotten dimmer, there is actually something more tangible going on than just the proverbial rose-tinted glasses of nostalgia! In this case, the truth lies in the eye of the beholder. 

Many organs in the human body can regenerate or repair themselves: the liver can get cut in half and re-grow, even the brain or heart can heal some forms of damage, albeit slowly. However, many parts of the eye cannot be naturally replaced or repaired. Things like small tears in the eye lens, which cause blurriness (much the same as scratching the lens of a camera), can at least be fixed. But sadly, it cannot do anything about the gradual discoloration that happens to the eye lenses over the years. Exposure to sunlight, especially ultraviolet (UV) light, can cause the normally clear eye lens to turn yellow. 

In essence, as the body ages, we end up having to look at everything through a gradually darkening filter. Like a tinted window, the more yellowed a lens becomes with time, the less light can pass through. That means less light can reach the light-sensing cells in the back of the eye (light-sensing “rod” cells or especially the color-sensing “cone” cells), causing everything to look dimmer. If there are spots that get particularly opaque, we call them cataracts.  

Fortunately, there is good news too. There are, of course, surgical procedures which can help fix the worst of these cases—like cataracts—that happen over time. What the body cannot fix on its own, we can often figure out how to fix! Besides surgery, there is other reassuring news. Even if visual acuity or peripheral vision decreases with age, our ability to perceive color does not appear to diminish badly within the vision that remains. We can still see the blues of our favorite lake, for example, or the pigments in our favorite painting, and find them much the same as we remember.

So in the end, perhaps the world really is a little brighter in the eyes of a child, in many ways. No matter what happens to our physical eyes, that could be something we all aspire to: whether admiring the patterns in your favorite mug, or watching the light beam from a smile of a loved one, we could all take a moment and “clean” our mental lenses to focus on the brightness—the good, in everything.