Imagine having a couple more hours until you have to get up for work, but can’t fall asleep. Or what about feeling sleepy when everyone around you is waking up? For someone living with Non-24-Hour Sleep-Wake Disorder, or Non-24, this is reality.

According to an article on the StrongGo® Industries website, Non-24 commonly affects those who are blind and happens when a person’s natural circadian rhythm is disrupted. This cycle of 24 hours is what causes us to both be more productive in the daylight hours and ready for sleep at night. When that rhythm is interrupted, it can result in the person losing out on those vital hours of sleep.

Usually, the optic nerve is able to send signs to someone’s brain that it’s time for bed. But when someone is blind and has Non-24, no signals are received. People can experience insomnia and have a hard time falling asleep or staying awake during the day. When there’s a change in the release of cortisol (a hormonal function that’s controlled by the circadian rhythm), patients can lose concentration and have immune issues and appetite changes. Some of the effects of Non-24 can cut into people’s social lives and can disturb their ability to work and perform other tasks. Non-24 isn’t easy to diagnose, and often, it’s mistaken for depression.

This disorder can affect about 70 percent of people who are blind. It is possible for Non-24 to occur in sighted individuals, but it is rare. Diagnosing the disorder is difficult; those patients who do have it may go for weeks with normal sleeping cycles. Some of the symptoms can include an urge to sleep during the day, waking up throughout the night and experiencing sleeping patterns different from other people.

But the good news is that there’s a greater awareness of Non-24 as a unique condition, and more work has been done to develop treatments. One drug called Helitoz can treat the disorder, but many people are denied access to it because it can cost $60,000 or more each year. Many people opt for cheaper treatments such as melatonin, which averages about $50 a year.

For people already navigating their world in total darkness, Non-24 may feel like an unfair extra burden. But today, people don’t have to face that burden alone. Help is out there. Share your story here.