Causes of Myopia, Nearsightedness

Have you ever heard that myopia can be caused by low exposure to the sunlight? 

I have recently come across a great article Urban Eyes by Nathan Seppa in ScienceNews that summarized current knowledge on reasons for developing myopia, and exposure to sunlight was among of the three main known causes of myopia. I will summarize the article in this post and hope that it can serve someone well.


Why do I care about myopia? My eyesight started getting myopic (nearsighted) when I was about 14 years old. No one in my family ever had bad eyesight. After years of researching (well, amateur researching) the reasons of developing myopia, I found a lot of conflicting data and no definite 100% causes of myopia.

The article that I mentioned in the first paragraph made me both hopeful and sad about my ability to get good eyesight back. But first things first. Let's see what the article mentions as main known causes of myopia:

1. Genes
2. Constant work with objects close to one's eyes (reading, working on a computer, etc)
3. Lack of exposure to sunlight

Genes

This reason seems to be quite straight-forward: if parents and/or relatives are nearsighted, their children are likely to develop myopia because they inherit genes that cause myopia. However, kids do not always develop myopia, or visa verse, kids develop myopia with all relatives never having it. So, genes are not an 100% predictor of having or not having myopia.

Close Distance Activities

This cause of myopia is a contradictory one. I have always been told by my parents to not read a lot, especially at night, not to watch TV or work on the computer for long times to protect my eyes. I did not listen much:). And here we come, I have myopia. I was always sure that it's a definite cause of myopia until one friend of mine said that it's not the cause. 

My friend found lots of evidence in studies that doing activities close to one's eyes do not affect eyesight in any way. She studied harder than me spending days in front of the monitor - and nothing! Her eyesight is perfect! I was very skeptical of her point, but her own example showed that doing work at close distance is not a 100% way into myopia. 

This piece of knowledge perplexed me. If working close distance was not something that caused my myopia, what could cause it instead?  The next cause of myopia gave me a glimmer of light in this confusion. 

Exposure to Sunlight

The article says that there is growing evidence that lack of exposure to sunlight can contribute to developing myopia. This study is an example of such evidence. This cause means that people may develop myopia not because they are doing it close to their eyes, but because they do this work in offices, in close spaces. Then, they come back home and continue doing other activities in the deem light provided by electric appliances. 

How exactly is sunlight keeping our eyesight healthy? According to the article, sunlight triggers release of dopamine in the retina that stops unwanted eye growth. It's only daylight that is intense enough to do that. Daylight delivers 28,000 to 130,000 lux (a measure of light intensity), while the average house delivers about 1,000 lux. The latter intensity may not be enough to release dopamine.  

[ The article doesn't explain well why unwanted eye growth is associated with myopia. Maybe you, reader, have an idea? ]

Another scientist proposes an idea that it's lack of vitamin D that may cause myopia. If people spend more time outdoors their bodies will produce more vitamin D. Though, this is not proved well yet. It's a tested observation.

All these studies talk mostly about effect of little exposure of sunlight on kids and not much on adults. While this cause of myopia gives me hope that by spending more time outside I can reverse my myopia, there are no studies yet that prove I can do that. It may stop the unwanted growth of the eyeball, but can it reduce its size? That is the question I am eager to find answers to in the near future.

Other Possible Causes of Myopia

Glasses

I read a lot how wearing glasses can worsen one's nearsightedness. Many doctors claim that it is not true, while people keep saying that doctors try to earn money by keeping prescribing stronger and stronger glasses. There are even many websites that explain how glasses for myopic vision make it worse and instead propose nearsighted people to wear reading glasses. I do not know which one is true and do not recommend anything to people. However, my own experience always proves me that keeping eye glasses away helps my vision to at least stay at a certain level while wearing glasses makes my eyesight blurrier and blurrier.

Stress

I mention this cause because I saw it somewhere. If I find a good resource, I'll add it later. Extra hard work that our eyes do today cause eyes to stress more. Extra concentration while watching dozens of youtube videos, writing hundreds of emails, reading many articles online - and all activities require focus and hard work of our eyes. When our ancestors even from 19th and 20th century did farming, they did not have so much stress on their eyes. In addition to that, they looked long distances which relaxes eye muscles.

Conclusion for myself

After reading all the articles, I created a little eye care program for myself:

1. Eye Exercise. I do eye exercises at least once a day.
2. Vitamins. I take vitamin A regularly.
3. Wearing glasses. I don't wear glasses unless I really need them.
4. Long Distance Look. Since I work all day on my laptop and then do homework, watch videos, etc on my laptop after work, I have to relax my eyes often. It's difficult to track how much time I stay concentrated at once while working on the computer. So, I created a Google calendar with pop-up reminders every 20 minutes (see below in this post) that force me to remember to look away from my computer. These reminders tell to follow the 20-20-20 rule that I found somewhere on the internet long time as a healthy computing advice. The rule says, "Look 20-feet (7 meters) away from the computer screen for 20 seconds every 20 minutes). You can add my Google calendar by clicking the "+Google calendar" button in the bottom right corner. Note: the Google calendar pop-up windows work only if I keep the calendar tab opened all the time.
5. Spend Time Outdoors. The hardest one is to spend more time outside. If I spend most time during the day in the office (when the daylight is the brightest), I end up having little time to spend outside. I try to eat lunch outside and do something outside right after work while the sunlight is bright (a job, read a book, etc). I do not know if it can help my eyesight. After all, my eyeballs may have grown much already, and I do not know if the growth is reversible. But it won't hurt me to spend some time outside where our ancestors spent most of their time anyway.

I hope this post gave you some insight in causes of myopia. I welcome your input, ideas, links to other good studies, and eye care tips. 

Be healthy and happy!