Differing eye colors can actually say some pretty interesting things about you physiologically. In some cases, they can even give some valuable medical information or, yes, even make you more likely to encounter a specific vision disorder.
Of course, it’s not the end of the world if you do have an eye color with a couple of associated issues. Most of the associations we’ll be talking about today are more fun than grave and should be seen as indicative of slight tendencies, not sweeping epidemics. Well, that’s the disclaimer gone, let’s talk eye color!
Already a relatively rare eye color, blue eyes stand to become even more uncommon, thanks to their recessive heritability. They’re also arguably the only eye color to have an obvious downside associated with them. Well, sort of a downside. People with blue eyes (and other, rarer light shades such as gray), tend to be more sensitive to light, with roughly 16 percent of them being particularly susceptible to glare, possibly thanks to the relative lack of light-absorbing pigments in their irises.
This tendency actually received some increased attention thanks to baseball. In 2011, outfielder Josh Hamilton revealed that a team doctor had told him that daytime hitting woes might actually result in part from his light blue eyes. The claim isn’t crazy, and it’s not a completely lame excuse. Light sensitivity can easily slash visual acuity when a sensitive individual is exposed to increased light, as when players search for a fly ball or track a pitch.
The revelation had light-eyed players worried, but it looks as though they don’t really have to be. A recent follow up from The Hard Ball Times saw writer Gerald Schifman tackle the question statistically and find, surprisingly, that players with light-colored eyes actually tended to hit more effectively during day games. As Schifman himself will tell you, this shouldn’t be seen as an exhaustive take down – the numbers sampled were small, light sensitivity only affects a few people, even in at risk populations, and after all, it’s possible that sensitive players simply wash out before the pros – but it does at least look like there’s no crippling sensitivity epidemic at work in the MLB.
Another uncommon color. Green eyes do share one unfortunate point in common with blue eyes. Both are relatively light on pigment, and while green-eyed folks don’t exhibit the same penchant for light sensitivity, they are apparently at increased risk of developing uveal melanoma – an eye cancer caused by UV exposure – as are blue and gray eyes.
But there’s a chance that light-eyed people might get something in return. While only one study conducted by a team of researchers at the University of Pittsburgh School of Medicine has shown it so far, light-colored eyes may be indicative of greater pain tolerance. Not only did they experience heat pain less intensely, they were also less likely to feel any lasting psychological effects from it. The same study also showed that darker eyes were indicative of a tendency toward anxiety as well as sleep disturbances. In each case, the difference was extremely minor, so don’t go testing your supposed superpower just yet.
By far the most common color at the moment. Brown eyes are widespread and show up in just about all ethnicities. Like blue eyes, brown eyes may come with a quirk that affects their owners’ athletic performance. Unlike blue eyes though, the news, though skimpy, is all pretty positive. A couple of different studies have shown that brown eyed people tend to have slightly faster reflexes and perform better at reactive athletic tasks. Of course, when we say slightly, we mean very slightly, and we’ll leave it up to you to judge the studies.
One study by a team of researchers from the University of Louisville took 125 college students and had them hit variously colored racquetballs. At the end of the trial, dark-eyed men had outperformed the rest of the participants. They determined that dark eyed people were better at reactive sports requiring quick reflexes, while light-eyed people were better at “self-paced tasks,” such as pitching a baseball or golfing. Another study, conducted at Fort Hays State University, working with elementary school-aged children found a similar connection.
So, another suspect superpower. That said, there is a benefit to having those darker irises. As mentioned before, the lighter your eyes, the more likely you are to develop a certain strain of cancer. UV exposure also seems to accelerate the effects of age-related macular degeneration, a serious sight disorder common among older people. Brown eyes are more densely pigmented and have an easier time soaking in rays without damage.
If we leave more commonly colored eyes behind, a few special, exotic cases begin to show up. Among them: heterochromia iridum, or two differently-colored eyes. Striking, and very rare in humans, heterochromia iridum can also be an indicator of Waardenburg syndrome, an unusual genetic disorder most known for causing deafness.
Albinism can also produce some different eye colors. “Red” eyes are actually just eyes with extremely little pigmentation, which allows the coloration of blood vessels to show through. And although it happens very, very infrequently, albinism can also produce the only true violet eyes ever seen in humans.
Eye Color and You
We’ll wrap this up from a more personal perspective. For the most part, eye color shouldn’t be seen as heavily indicative of medical risks or functional advantages. Most of the differences found between them are too slight to make serious blanket statements about any eye tones.
There is one big exception – the general susceptibility of light-colored eyes to sun damage. If you do have light blue or green eyes, then we’d recommend being extra cautious about wearing sunglasses. Apart from that though, eye colors are generally a cosmetic difference and odds are they aren’t about to handicap your career as a baseball player.