Prevalence
While both sighted and blind people are diagnosed with Non-24, the disorder affects more totally blind individuals than sighted.
The European portal for rare diseases, Orphanet, lists Non-24 as a rare disease by their definition: 1 person per 2,000 or more. There are about 140,000 sufferers of Non-24 in the European Union; a prevalence of approximately 0.03%, or 3 per 10,000.
It has been estimated by researchers that of the 1.3 million blind people in the U.S., 10% have no light perception at all. Of that group, it is estimated that approximately half to three-quarters, or 65,000 to 95,000 Americans, suffer from Non-24.
Read more about this topic: Non-24-hour Sleep-wake Disorder
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