Golden State Warriors guard Steph Curry is a legendary sharp-shooter—perhaps the greatest ever in basketball history. So vision problems may not be the first thing that comes to mind when you think of him—or the second thing or even the third.

But as the 38-year-old Curry recently discussed with me, he has been dealing with keratoconus, a progressive eye disorder. This is the man who already has made more three-pointers in his career than any other NBA player ever and has the highest career free-throw shooting percentage in NBA history. But for much of his basketball career he was dealing with vision problems.

Curry Didn’t Realize He Had Keratoconus

Chances are you and many other fans had no “eye-dear” about this issue with the four-time NBA champion, two-time NBA Most Valuable Player and 12-time NBA All-Star. Neither did Curry, for years. In fact, it wasn’t until the 2018 NBA season when Curry, who had already been named to the All-NBA first team twice, got a comment that forever changed his view on things.

“I was on the bench during a road game when our then GM Bob Myers, had reached out after the game,” Curry recalled. “And he was like, ‘Hey, the camera was on you for most of the time when you were on the bench and do you know how much you squint?’” Curry added that he had never thought about this and “based on that subtle little call out,” went to get his eyes checked.

Curry Then Found Out What Keratoconus Is

That’s where an eye exam revealed that he had keratoconus, a condition that Curry had never heard of previously In fact, if you ask much of the public about keratoconus, you might get a response like “karate, what? Karate cones?” Keratoconusm which is actually pronounced “ker-uh-toe-KOH-nus” and can be abbreviated with a “KC,” has nothing do with kicking down traffic cones. Instead, it occurs when the cornea that sits at the front of your eye gets progressively thinner and steeper so that it bulges forward from a dome-shape into more of a cone shape.

Since light and everything from the outside world first goes through the cornea before getting processed as images via the eye and brain, such a deformation of the cornea can lead to different visual symptoms such as blurred or distorted vision, frequently changing glass or contact lens prescriptions and increased bright light and glare sensitivity. I’ve covered before in Forbes how any changes in the cornea can lead to a host of “eye-carumba” problems. Curry also realized in retrospect that keratoconus was responsible for the mild headaches that he would periodically get.

“I learned about keratoconus pretty quickly and about irregular shape of my cornea and just how distorted my vision really was,” Curry explained. “And there was a need for us to follow up testing, every six months to make sure that it didn’t progress because it is an eye or a sight threatening condition.” The cause of keratoconus remains unknown, although there are risk factors such as having a family history of KC and rubbing your eyes vigorously.

Curry Got Special Contact Lenses For His Keratoconus

It was eye-opening revelation for Curry in many ways. The doctor fitted Curry with special contact lens that can help compensate for the cornea deformation and correct vision. “Once I got to actually see what the world looked like, it was kind of an odd odd moment," he mentioned. "But also kind of scary at the same time knowing that had I not gotten that text from Bob Myers or had I not had access to go get screened, there’s a potential for it to go the wrong way.”

The wrong way includes various complications and irreversible eye loss. For example, cornea swelling and scarring can occur. In addition to corrective lenses or glasses, some people may end up getting a corneal collagen cross-linking procedure to try to slow or halt the progression of keratoconus. KC that progresses too far can necessitate a cornea transplant—and anything with the word “transplant” in it is a serious situation. For now, Curry’s KC management consists of wearing his lenses and keeping up with the half-year eye checks.

Prior To His Keratoconus Diagnosis, Curry Unknowingly Compensated

Curry added that he wasn’t aware of his vision issue prior to that eye check in 2018 and “was kind of just finding ways to get around it. And then on the court, that’s just the way the world looked and me looking at the scoreboard. It just never dawned on me that my eyesight was deteriorating year after year.” That’s what happens when you don’t have normal vision to compare and contrast with at the time. He added, “It was just you made the necessary adjustments, which was an interesting way to go about it.”

Again, this was the person who holds the record for most three-pointers in an NBA season and who had never used any corrective lenses previously. “It’s our running joke in our family and around the team,” Curry relayed. “Like ‘You’re telling me the whole time you couldn’t see?’ I was like that up until like basically half of my NBA career.” Curry believed that maybe “the muscle memory of it all” had helped him maintain his shooting prowess, despite the not-really-being-able-to-see-clearly thing.

Curry Is Trying To Raise More Awareness About Keratoconus

Curry sees how his experience could help others. That’s motivated him to partner partner with Glaukos for the “Could it be KC” campaign to help people recognize the signs of KC, talk to eye care professionals about it and understand the potential treatment options. Curry has also shared his experience through a new picture book entitled, “Eye on the Ball.” He feels that it is especially important for kids and their parents to be aware of KC because such vision issues could significantly affect learning and development.

Even though Curry didn’t get diagnosed until he was 30 years of age, KC typically first emerges in the teen years and then progresses most aggressively in the twentysomething years. So it can be an important something to get teens screened early enough, especially if they have a family history of KC, so that proper interventions may be put in place to potentially prevent irreversible vision loss. An important part of the campaign is raising awareness of KC among Black and Hispanic populations, who are disproportionately affected by KC. By the way, I’ve already covered in Forbes some of Curry’s work with different communities on building resilience.

In general, it is important to keep more of an eye on, well, your eyes. And that means getting objective eyes on them, like those of an eye care professional doing a real eye exam. That’s because you may not be able to see what changes are occurring. You may even unknowingly compensate for any vision issues, such as becoming widely regarded as the greatest shooter in basketball history.