The Surprising Reason Cavemen Probably Had Better Vision Than You
Imagine a nearsighted caveman trying to hunt or outrun a predator - the outcome looks grim. He may suffer the embarrassment of putting a spear through a lion-shaped bush; if things go poorly, he ends up on the menu. So how did ancient people deal with myopia?
The surprising culprit: the rise of nearsightedness.
Unfortunately, there weren’t cavemen with clipboards making observations about eye health back then. However, recent increases in the number of people who are nearsighted suggest that it may be a relatively modern problem. This is supported by studies in China, Taiwan, and the United States.
Today, up to 90% of Chinese teenagers and young adults are myopic when just sixty years ago it was closer to 10-20%. Not only that, stark increases have been seen in the US and Europe (50%, up from 25% fifty years ago). Another study in the US showed that myopia jumped from 25% to 42% in thirty years and that the instances of moderate severity also doubled during the same period.
While typical cases of nearsightedness can be corrected with glasses, contact lenses or Lasik surgery, there are more severe types that cannot. The truly severe cases can result in long-term eye problems such as cataracts, glaucoma, retinal detachment or blindness. East Asia is also seeing an increase in these severe cases of myopia with up to one-fifth of young adults having it.
Causes of Increased Myopia
What is the cause of the increase in myopia? Once believed to be caused by spending too much time focusing on nearby objects like books, studies now suggest (though they are not conclusive) that myopia may be caused by not spending enough time outdoors. Spending time outside results in bright light exposure and focusing farther away which is good for eye health. Natural light has also been proven to increase dopamine production, thus regulating eye growth and decreasing the likelihood of myopia.
This finding is particularly relevant now with the popularity of electronic devices and gaming. It would stand to reason that children and young adults spend more time indoors and less time outdoors.
Wondering what you can do to prevent myopia in your own children? According to one myopia researcher in Australia, 3 hours of outdoor sun exposure per day is needed to prevent myopia. That is about the equivalent of wearing sunglasses on a sunny day or standing in the shade outside. This means encouraging children to put down their devices and spend more time outdoors. This can include studying outside, playing, athletics, walking, etc.
If your children must remain indoors, you can teach them the 20-20-20 rule which helps to reduce eye strain. Every 20 minutes, take a 20 second break, and look at something at least 20 feet away. However, what matters most is exposure to bright light, something that can’t be achieved indoors so encourage them to get outside and enjoy the day.
If you or a family member is experiencing symptoms of myopia or any other vision-related issue, we encourage you to schedule a comprehensive eye exam with a doctor from our network. It’s easy with our Find a Doctor Tool.