An alternative to the light box is a light visor, which is sold commercially by medical specialists. Patients may feel confined by sitting with the light box every morning. In cases where early morning sunlight is plentiful, a patient may find that he or she feels better walking outside while wearing the visor. During exposure to light therapy, it is important to take the same precautions that one would take with exposure to normal sun and bright light. Also, because bright light therapy can adversely affect vision in certain cases, a physician should assess conditions and diseases of the eye prior to treatment.
Some patients feel hyperactive after routine bright light therapy and others experience headache.
These factors define individual exposure levels and frequencies. Finally, patients with DSPS should avoid bright light exposure in the early evening because early evening light exposure tends to delay sleep onset. Back to Top Chronotherapy Chronotherapy was the original treatment for DSPS, first suggested by C.A. Czeisler in 1981. Chronotherapy is used to manipulate the sleep-wake cycle in an attempt to change the patient s underlying circadian rhythm. Specifically, the patient progressively goes to bed and wakes three hours later than the night before, until he or she moves around the clock and can consistently sleep earlier.