shape of sightKeratoconus used to be called rare: 1 in 2,000. A large study with modern imaging found it in 1 in 204 adults, and it usually starts in the teen years. If your prescription keeps changing, ask your eye doctor about it. #WorldKCDay #Keratoconus
keratoconus is ten times more common than we were taught.
For decades the textbook figure was 1 in 2,000. A large study using modern corneal imaging found it in 1 in 204 adults. It usually starts in the teen years and can look like ordinary astigmatism. Treatment can stop it from getting worse but can't undo damage already done, so awareness matters.
Tap a stage to see how keratoconus can change vision
Axial curvature map
moderate
Kmax 53.0 DI–S 0.0 D
Illustration only, not a vision test or a real scan. It mimics the color-coded curvature maps from a corneal topographer: cooler colors are flatter, warmer colors steeper, in diopters (D). Kmax is the steepest point; I–S compares the lower and upper cornea. Real scans and symptoms vary.
- prescription keeps changing
- ghost images
- halos around lights
- trouble seeing at night
- light sensitivity
- frequent eye rubbing
- squinting and headaches
- 1 in 204
adults had keratoconus in a German study of 10,419 people screened with corneal imaging.1
- 1 in 251
children had it in a pediatric screening study, rising to 1 in 72 when suspected cases were counted.2
- 1 in 8
keratoconus patients evaluated from 2015 to 2020 received cross-linking, the treatment designed to stop progression.3
a dome that slowly becomes a cone
The cornea is the clear window at the front of your eye, and it does most of the eye's focusing.
Collagen fibers hold it in a smooth dome. In keratoconus those fibers weaken, so the cornea thins and bulges outward into a cone. Light no longer focuses to one point, and vision blurs, smears and doubles in ways glasses can't fully fix.
It usually starts between the early teens and mid twenties, affects both eyes (often unevenly), and can keep worsening for years. Researchers think most cases involve inherited factors plus a trigger, most often chronic eye rubbing.5
tap anything that sounds familiar
Early keratoconus can feel like ordinary nearsightedness or astigmatism. Tap any signs that apply to build a list to bring to an eye exam.
what a regular vision test can miss
Reading an eye chart shows how well you see. It doesn't show the shape of your cornea. A corneal scan (topography or tomography) maps it, and it's quick and doesn't touch the eye.
| What it checks | eye chart and prescription | corneal scan |
|---|---|---|
| Measures how sharply you see | Yes | Not its job |
| Sets a glasses prescription | Yes | No |
| Maps the curvature of the whole cornea | No | Yes |
| Shows early cone-shaped changes | Can miss them | Yes |
| Tracks changes in the cornea over time | No | Yes |
Player spotlightLiving with keratoconus
In his words“For a long time, I got used to just getting by, squinting and brushing off headaches.”
Stephen Curry, 20267
One of the best shooters in NBA history was playing through blur.
51–1353PT made–attempted, Feb 20199
.3783PT pct in that slump9
2Titles won before diagnosis7
6 moBetween follow-up eye tests10
Bottom line
If it went unnoticed in a two-time MVP, it can go unnoticed in a ninth grader.
Shape of Sight is independent and is not affiliated with Stephen Curry, the Golden State Warriors or the NBA.
most treatments help you see. one is designed to stop progression.
myth or fact? flip to find out.
the treatment exists. too few people get it in time.
Cross-linking is designed to stop keratoconus from progressing, but in one large study only about 1 in 8 patients received it.3 Common barriers include late diagnosis, insurers that may require proof the disease is worsening before approving treatment, and public coverage that varies by state.3,6
What we're asking for. Tap each to see why.
01corneal screening for at-risk kids
Children with allergies, eczema, Down syndrome or a family history whose vision keeps changing should have access to a corneal scan, not just a new prescription. Pediatric studies show keratoconus is far more common in kids than once believed.2
02faster approval for young patients
Keratoconus can progress faster at younger ages. Rules that require documented worsening before approving cross-linking can mean a teenager loses vision while waiting.3
03coverage for every FDA-approved option
04Medicaid coverage in every state
The American Academy of Ophthalmology has pushed states such as New York to cover cross-linking under Medicaid for progressive keratoconus.6 Access shouldn't depend on where you live.
five minutes you can spend today
Write to someone who can change a policy, share the facts, or bring good questions to your next eye appointment.
letter builder
questions for your eye doctor
- Could these symptoms be related to the shape of my cornea?
- Would a corneal scan (topography or tomography) be useful for me?
- If it's keratoconus, how will we track whether it's changing?
- Which treatments or lenses might fit my situation?
- Should family members be checked too?
Steph Curry won NBA titles while squinting through keratoconus without knowing it. If it can go unnoticed in an MVP, it can go unnoticed in a teenager. Get regular eye exams. #WorldKCDay
One habit is linked to keratoconus getting worse: rubbing your eyes. Itchy eyes? Ask an eye doctor about relief instead of rubbing. #WorldKCDay #Keratoconus
common questions
General information only. An eye care professional can tell you what applies to you.
can keratoconus cause blindness?
Total blindness from keratoconus is rare. Without treatment, though, it can blur vision enough that glasses stop helping, and some people eventually need a corneal transplant.
is it genetic?
Partly. About 10 to 20 percent of people with keratoconus have a family history of it.12 Researchers think most cases involve inherited factors plus triggers such as chronic eye rubbing.
can someone with keratoconus get LASIK?
Surgeons generally don't offer LASIK to people with keratoconus, because it removes tissue from a cornea that is already thin. Screening before LASIK looks for signs of it.
does insurance cover cross-linking?
Many plans cover the FDA-approved epithelium-off procedure for progressive keratoconus, but policies vary and some require proof of progression first. The National Keratoconus Foundation offers to send an advocacy letter to a patient's health plan.13
when do people usually bring it up with an eye doctor?
Often when a prescription keeps changing, glasses don't give sharp vision, a close relative has keratoconus, or someone rubs their eyes a lot. The eye doctor decides which tests make sense.