A Self-controlled Study of the Effect of Partial Spectral Absence of Visible Light on the Pupil

The Impact of Partial Visible Light Spectrum Absence on Pupil Response and Autonomic Nervous System Excitability: A Cross-Over Randomized Controlled Trial

Previous studies have shown that the spectrum of light influences myopia. LED lights with a partially absent light spectrum increase the risk of myopia progression compared to LEDs with a full spectrum, potentially mediated by the excitability of the parasympathetic nervous system. This study intends to compare pupil size and area, as well as parameters regulated by the autonomic nervous system (such as skin bioelectrical activity and heart rate), between LEDs with a full visible spectrum and LEDs with a partially absent spectrum around 470nm and 730nm. We aim to elucidate the physiological mechanism underlying the effect of light spectrum on pupil changes and myopia.

Inclusion Criteria:

• 1. Age 7-45 years 2. Able to wear multi-channel physiological measurement devices and cooperate with experimental procedures.

  3. Binocular? spherical power between -0.50 to -5.00 diopters, and cylinder power no more than -1.50 diopters.

  4. Voluntarily participate in this study with informed consent form signed.

Exclusion Criteria:

• 1. History of diseases affecting autonomic nervous system function, such as depression and anxiety.

  2. History of eye diseases such as strabismus, amblyopia, keratitis, and glaucoma, which are unsuitable for eye movement test.

  3. History of major systemic diseases or surgeries such as cranial surgery, myocardial infarction, or stroke.

  4. Systemic medication history that may affect autonomic nervous system function, including but not limited to antidepressants, antihistamines, anticholinergics, antipsychotics, and sedative-hypnotic drugs like diazepam or lorazepam.

  5. Use of eyedrops such as mydriatics or miotics that will affect pupil size. 6. Having difficulty in understanding and cooperating with the trial, such as those with disabilities, communication barriers, or those unable to undertake examinations.

  7. Other contradictions that the physician may consider inappropriate for enrolment.