Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned.

The primary goal of this study is to identify the presence of desynchronized circadian rhythms in 25 children by measuring melatonin secretion in serial blood or saliva samples, and to rule out any primary sleep disorders.

Subjects will complete 25-hours of hourly salivary, plasma sampling biweekly. Melatonin will be measured in urine, for children under the age of 3. Sleep and behavioral questionnaires will be completed by parents and/or teachers. This study involves an optional, 1-year melatonin treatment sub-study, in which the children will take 0.1 - 3mg daily. A second optional sub-study involves a study of the child's sleep through polysomnography, in order to identify possible sleep disorders.

Inclusion Criteria:

• Age 1-20 years
• Blindness for the past year (verified by an ophthalmologic exam), but otherwise in general good health.

Exclusion Criteria:

• Abnormal heart, lung, kidney, liver disease or a primary sleep disorder,
• Significant clinical abnormalities (other than blindness),
• Use of medications with known effects on melatonin metabolism (e.g. beta-adrenergic blocking drugs or tricyclic antidepressants).

The PI has retired from the institution. Sincere efforts were made to contact the PI/study team members, but were unsuccessful. No study data are available.

The PI has retired from the institution. Sincere efforts were made to contact the PI/study team members, but were unsuccessful. No study data are available.

Analyses were not completed because, a unique provision in the American Recovery and Reinvestment Act (ARRA) of 2009 funding source unexpectedly prevented approval of a second year no-cost-extension in which completion of analyses were planned.