Can morpheus inadequacy bring about myopia?
Make sure adequate morpheus is beneficial to eye health, but can you prevent and control myopia?To answer this question, I did some research and found that this question is not simple, it’s a very cutting edge, very complex area…What is the biological clock (circadian rhythm), which starts with the sunrise and ends with the sunset, is called the circadian rhythm.Circadian rhythm is a 24-hour biorhythm that is an autonomous molecular timekeeping mechanism based on cells.The body clock regulates the daily rhythms of sleep and wakeup, blood pressure and heart rate, exercise, hormone secretion, body temperature, metabolism and many other physiological processes, most of which are controlled directly or indirectly by the “master clock” in the hypothalamus suprachiasmatic nucleus (SCN).The biological clock (circadian rhythm) is mainly regulated by ambient light. Ambient light is the most important factor in maintaining the biological clock, so light is closely related to circadian rhythm.Melanopsin,Intrinsically photosensitive retinal Ganglion cells (ipRGCs) is a photosensitive pigment with the characteristics of direct sensing.Opmelinin is similar to rod and cone proteins, but its action spectrum is different, with a maximum absorption range of 484nm (blue light).It transmits light stimulation signals to the circadian rhythm control system, the suprachiasmatic nucleus (SCN), through a series of signal cascades in the retinal hypothalamic tract.The main role of ipRGCs is to regulate the release of melatonin in the pineal gland.Daytime natural light contains blue light (484nm) to suppress melatonin secretion, which makes people energetic.When the sun goes down and there is no blue light (484nm), melatonin production increases, making you drowsy — as if reminding you it’s time to sleep.The relationship between light and rhythm changes is the basis for treating jet lag, such as the glasses now designed to help with jet lag.The glasses emit light of a specific wavelength to stimulate the suprachiasmatic nucleus of the hypothalamus (suprachiasmatic nucleus) to regulate (stimulate or suppress) melatonin levels at different times of the day, regulating the circadian rhythm of the wearer’s body clock to help combat jet lag.Back in 1957, Jensen reported in the journal Science that constant darkness or constant light (disrupting circadian rhythms) could affect refractive development in chicks. He hypothesized at the time,The absence of a normal circadian rhythm (light/dark cycle) can lead to abnormal eye growth and refractive errors.In recent years, there has been increasing evidence that circadian rhythms are involved in eye growth and refractive development.The eye axis and other anatomical and physiological features of both humans and animals are affected by circadian rhythms.1. There are Many Differences between Artificial and Natural Lighting Compared to the ancient people who worked with the sun and rested with the sun, modern artificial lighting (the increase of night lighting) has turned our way of life upside down.And lighting technology is developing rapidly, from the early incandescent lamp to fluorescent lamp, LED (light emitting diode) lamp, different lighting spectrum and brightness are also changing.During the day, we usually work indoors, and the indoor lighting is different from that of nature. When the sun goes down, we are subjected to artificial lighting of different intensity and spectrum: TV/movies to watch, mobile phones/ipads to play, and artificial lighting of different types, intensity and wavelength at any time and anywhere…The difference between natural and artificial lighting is as follows: 1. Indoor lighting intensity is generally between 100 and 500 lux;Outdoor natural light illuminance is between 1,000 and 100,000 lux, depending on atmospheric conditions.The circadian rhythm of melatonin secretion can be quite different in outdoor and indoor environments (including artificial lighting during the day and at night).2. Lighting at night is complex. Large areas of artificial lighting and reflection/refraction of light by clouds/dust will illuminate the whole sky, forming the diffuse light of the night sky (excluding the moon, stars and other natural light).Cloudy days are cloudier, producing a more diffuse light in the night sky than on a clear night.And the brightness changes very quickly as cloud cover changes.3. Light-emitting electronics such as televisions, computers and handheld devices (which emit blue light to suppress melatonin) can disrupt normal sleeping behavior in children and adolescents, leading to circadian rhythms disruption.A retrospective study of 479 children, published in nature in 1999 (Quinn, 1999), found that children who slept with the light on at night before the age of 2 (48.4%),Nearsightedness is five times more common than sleeping with the light off.This research result was very surprising, but after that there are multiple studies to prove that “turn on the light at night to sleep easy to myopia”, this thesis has failed to repeat the results, scholars put forward different opinions, they found a nursery when the children go to bed at night lighting at night or not has nothing to do with the development of myopia, and think that people who many parents for children to sleep with the light open is short-sighted,Maybe it’s inherited myopia rather than sleeping with the light on.)Someone asked, I do not understand why children at night to turn on the light to sleep, sleep on the light will lead to sleep?Why did a whopping 48.4% of parents in the study do so?In animal studies (Nickla, 2016), 2 hours of light exposure at midnight caused “acute” axial growth in chicks for the next 6 hours.It is suggested that night light changes the rhythm of eye axis and choroid thickness, and the imbalance of circadian rhythm may lead to myopia.The retina is the only light-sensitive organ in vertebrates, and the light signal from the retina is the basis of the central control of circadian rhythm.During the day, people who should be outdoors (in a high-light environment) live indoors (in a low-light environment), and at night, people who should be sleeping live with artificial light, which disrupts circadian rhythms.Robinson J (1991) reported that the average light transmittance of adult eyelid to 700nm light was 14.5%, and that of newborn eyelid was 21.4%. The light transmittance of eyelid to 580nm light decreased to less than or equal to 3%.Ando K (1996) reported that the light transmittance through the eyelid was 0.3% blue light, 0.3% green light and 5.6% red light, so the eyelid was equivalent to a red filter.This suggests that eye closure does not completely block the effects of light on circadian rhythms.Even while sleeping, light can reach the retina (especially incandescent bulbs or sources rich in long-wavelength red light) and affect circadian rhythms.Jee (2016) A study of 3,625 Korean adolescents found a negative association between sleep duration and myopia, with less sleep associated with increased myopia (0.10-d increase in myopia for every 1 hour of sleep loss).Ayaki’s (2016) survey of 486 myopic patients aged between 10 and 59 reported that children’s sleep quality was related to myopia, among which the high myopia group had the most severe impact.Zhou (2015) conducted a survey of 1970 children with an average age of 9.8 years and found that myopia and sleep disorders were common in children, but there was no correlation between them.These studies talk about a correlation between nearsightedness and lack of sleep, but they can’t say cause and effect, meaning it’s impossible to know whether nearsightedness causes sleep deprivation or sleep deprivation causes nearsightedness.Suggestion: The author believes that it is not lack of sleep that causes myopia, but the disturbance of circadian rhythm caused by changes in light.For example, sleep in a dark environment (just not falling asleep) did not promote nearsightedness.And if you don’t sleep in a bright environment, it may promote nearsightedness.So it is very important to go to sleep at the right time. If you want to learn more, listening to audio learning in the dark at night will not cause myopia.If children study and read indoors, daytime, relatively high illumination is better, which is in line with the natural light-dark cycle;It is not advisable to stay up late at night (especially late at night) to study and read, because late at night using high-intensity light source conflicts with natural biological rhythm (and low light will also promote the progress of myopia).The sooner you finish your homework, the better. Don’t put it off until late at night.Going to bed early and getting up early in conjunction with natural light and darkness also seems to be beneficial in preventing and controlling myopia.Many school assignments require electronic devices (cell phones, ipads, etc., which emit blue light that inhibits melatonin) to complete, but be warned: use them early, not before bed.It is recommended to do electronic work before paper work to minimise the impact of artificial lighting (especially blue light) on the clock.Children sleep with the lights off, and bedroom curtains to block the effects of “light pollution” at night.The study of Hughes (2015) suggested that light induced the least change in biorhythm at noon (when the light was the strongest), so increasing outdoor activities (including reading outdoors) at noon might have the best effect on myopia prevention.Some people may ask that melatonin is a medicine for adjusting jet lag and improving biological rhythm. Then, can taking melatonin before bed control myopia?The role of melatonin in the regulation of eye growth is still unclear, and its effect on myopia is very complex and has not been clearly studied at present.In animal studies, intraocular melatonin injection (Hoffmann, 1996) or systemic melatonin injection (Summers-Rada, 2006) did not control ocular axis growth in small corns.As a warm reminder, parents should be cautious about using melatonin, because melatonin can have side effects.In summary, circadian rhythm has an impact on eyeball growth, refractive development and myopia, but the mechanism is very complex (some research results are even contradictory), which has not been clearly studied.But it is a new direction of myopia prevention and control, which can put forward new guidance on the prevention and control of myopia when to do outdoor activities, when to read, when to sleep.(The author is Mei Ying, director of Meishi Beauty Eye Center, Shanghai New Hongqiao International Medical Park