Many aspects of your health are affected by the quality of your sleep. Apparently, eye health is one of those. We do not know if sleep apnea causes keratoconus or if it is the other way around, but the researchers found a strong association between the two health conditions. In other words, if you have sleep apnea, the odds are likely for you to have keratoconus as well.
A University of Michigan study published in the Journal of Ophthalmology found a link between sleep apnea and keratoconus, which causes your cornea to become cone-shaped and leads to vision problems (nearsightedness) and astigmatism. Sleep apnea, as you are likely aware, interrupts your breathing cycle because your airway is blocked. You may or may not wake up during an apnea episode, which is why sleep apnea is life-threatening.
A higher prevalence of keratoconus was also noted for people with Down Syndrome and asthma.
Keratoconus is also called conical cornea. Research suggests that excessive oxidative stress from free radicals (pollution), sun damage, and scar tissue from contact lenses can lead to a cone-shaped cornea. The cornea of your eye actually bulges slightly, creating an abnormally shaped cornea and abnormal vision. Symptoms of blurry vision and sensitivity to light in one or both eyes may start in your late teens or 20s.
One might wonder if the connection between sleep health and eye health has to do with the quality of sleep. The body heals, repairs, and restores itself during sleep. Without it, those repairs are left undone. This put your immune system at a disadvantage, and increases the risk of disease, and apparently, vision loss.