Contributor Lynne Lamberg – Improving Sleep and Alertness in the Blind – A Five Part Series

Part 3: The search for ways to reset inner clocks

Derek Naysmith lost his sight in 1986 when fireworks at a community display misfired and hit him in the face. “I am lucky to have survived,” he said. Both eyes had to be removed. He was 33 years old.

Naysmith, who lives in Edinburgh, Scotland, noticed changes in his sleep pattern almost immediately. “I fell asleep later and awakened later,” he recalls. “Sometimes I fell asleep in the daytime. I moved around the clock roughly every 24 days. I felt grumpy. I was out of phase with my work and my family.”

A lecturer in soil physics before he lost his sight, Naysmith moved into information technology, becoming a computer analyst and designer of data base systems.

A request to members of the British Computer Association of the Blind seeking volunteers for a sleep study at the University of Surrey, in Guildford, connected him with Steven Lockley. Naysmith enrolled in Lockley’s studies, starting around 1995. He completed questionnaires, kept a sleep and mood diary, recorded body temperature, and provided urine samples. This research confirmed that he had N24HSWD

As part of the study, he started taking melatonin, a hormone found to have body-clock resetting properties. “That made life bearable,” Naysmith said.

“I had a young family,” he noted. “Before I started using melatonin, I often missed out on family life. I might have had to go to bed around the time the kids came home from school.”

Now 57 years old, Naysmith continues to rely on melatonin, taking 4 mg. at 9:30 p.m. daily. “I go to bed between 10 p.m. and midnight, get up between 6 and 7 a.m., and have a normal day,” he said.

In his current work as a computer consultant, Naysmith strives to improve web accessibility for visually impaired people. He also devises auditory and tactile ways to convey data from graphs and charts.

Researchers began trying to synchronize the sleep/wake cycle in blind individuals with melatonin supplements in the late 1980s. Previous laboratory research had shown that daily injections of melatonin could synchronize the rhythms of rats kept in constant darkness.

In 1988, biochemist Josephine Arendt and colleagues at the University of Surrey reported they had given melatonin supplements by mouth to a blind man when his natural melatonin secretion started close to his desired bedtime. The melatonin locked his daily schedule of sleeping and waking in place. Subsequent studies showed melatonin supplements could synchronize body clocks in blind individuals.

Melatonin, a naturally-occurring hormone secreted by the pineal gland in the brain, is the biochemical signal of darkness. It serves as an internal marker of whether it is day or night. Because night length changes over the year, melatonin also serves as an internal indicator of whether it is summer or winter.

In sighted individuals, melatonin secretion usually starts several hours before bedtime, typically around 9:30 p.m. to 10 p.m. Melatonin levels stay high through the night, and taper down toward morning. Exposure to light at night turns off melatonin secretion.

Humans are day-active creatures. Melatonin onset tells the body that it is night, and the right time to sleep. When people, sighted or blind, attempt sleep in their biological night, they usually sleep better than they would if trying to sleep in their biological day. Melatonin taken in pill form may induce mild sleepiness. It is especially likely to cause sleepiness if taken in the daytime, when the body does not normally produce melatonin.

The potential of melatonin treatment to help shift workers adjust to schedule changes, travelers flying across multiple time zones to avoid jet lag, and people with other circadian sleep disorders to realign their body clocks is an active focus of current research. In all these situations, the dose of melatonin and time it is taken govern its effects. Some doses and times help body clock adjustment. Others hinder it.

Part 4 of this report discusses additional melatonin research.

Link to Introduction from the Editor:

Link to Part 1:

Link to Part 2:

One Comments

  1. I am pleased to discover articles about this issue. It is something that I have suffered with for a long time. I thought that I was the only one who suffered with the problem, because none of my totally blind associates mentioned it. Although I do recall an article about Stevie Wonder which commented on his odd sleep schedule.

    I have been searching for a web forum or some other method of connecting with people who suffer from this disorder. If you come across one, please let us know.