Near-sighted cell discovered in retina

Researchers have discovered a cell in the retina which may control the growth of the eyeball and the cause of myopia.   It also seems that indoor light might stimulate this cell to increase the amount of nearsightedness one develops.  This contributes to the observation that kids that spend more time outdoors tend to be less nearsighted.

Read more here.

Dr Michael D. Nelson, OD

 

How Do I Prevent Nearsightedness?

There is a nearsighted epidemic going on in the world.  In the 1970’s about 20% of NorthAmerican and Asian 20 year olds were nearsighted.  Now it is about 40% of North American and 96% of Asian 20 year olds.

While we don’t fully understand why or how, studies seem to indicate that more time spent outdoors seems to protect against becoming nearsighted.  Studies show that about 90-120 minutes outdoors in the sun can reduce nearsightedness.  What we do know is that it is not related to amounts of upclose work, as the studies have corrected for that.  In fact, there are some schools in Taiwan that have ‘bright-light’ classrooms where the walls and ceilings are made of see through plastic and these students seem to be less nearsighted than in other schools.

So get outside!!!

Cure to Asia’s Nearsighted Epidemic

Reading electronic devices in the dark

6a00d8354fadbd69e2017c38875f51970b-pi-1A recent article in The Wall Street Journal highlights an age old vision question and a modern day question.

Does reading in the dark harm your vision?  There is no evidence that reading in the dark  will cause any long-term damage to the eyes or change to the physiology to the eye.  It may cause some eyestrain or fatigue but there is no indication that this will increase myopia (nearsightedness) or harm your eyes.

Does reading on a tablet damage your eyes?  Studies comparing various fonts, displays and pixel resolution found no difference in the effect on the eye between reading e-ink or a printed book.  So if reading a printed book in dim light is okay, so i reading a Kindle.  One difference though, is that devices like ipads, iphones and LCD monitors all emit a lot of light in the blue end of the spectrum (just think about that familiar blue glow you get from these screens).  Blue light is known to scatter more and can cause increased eye fatigue.   The good news is that lens companies are starting to produce coatings, like the Nikon SeeCoat Blue, that selectively filter out this blue light and reduce eye fatigue.

Michael Nelson OD, Waverley Eye Care

Myopia/Nearsightedness

NEARSIGHTEDNESS

Nearsightedness, or myopia, as it is medically termed, is a vision condition in which near objects are seen clearly, but distant objects do not come into proper focus. It occurs when your eyeball is too long or the cornea has too much curvature, and light entering the eye is not focused properly. Some evidence supports the theory that nearsightedness is hereditary. There is some evidence that nearsightedness may also be caused by the stress of too much close vision work.

Nearsightedness is a very common vision condition that affects nearly 30 percent of the Canadian population. It normally develops in school age children. Since the eyes continue to grow during childhood, nearsightedness usually occurs before the individual reaches the age of 20.

You may need glasses part-time or full-time to enable you to see more clearly. If your condition warrants, your Doctor of Optometry will prescribe corrective lenses for you. You may only need them for certain activities, like watching television, going to a movie or driving a car.

Eyeglasses or contact lenses optically correct the problem by altering the way the light images enter your eyes, but they do not cure nearsightedness. At present there are no proven cures for nearsightedness. Surgical procedures such as LASIK and/or ocular implants may eliminate your need for glasses.

Michael D. Nelson

Myopia and Month of Birth

Recently a researcher out of Tel Aviv University’s Goldschleger Eye Research Institute studied 300,000 children, examining the association of nearsightedness with thier month of birth.

They found that those born in June or July have a 24 per cent greater chance of becoming severely myopic(> -6.00), than those born in December or January.

“Such findings might suggest that the amount of light exposure generates a biological signal that can influence the emmetropization process [the stage of life when the length of the eye and its focal ability are balanced out],” the study’s author said.

The authors stress that myopia can be caused by other factors — such as genetics —and that only 2.2 per cent to 5.6 per cent of severe myopia can be attributed to the season of birth or perinatal light.

So what does this mean to me – well I was born in May and I am only mildy myopic (-1.75).  A quick mental poll of our staff and we have only one staff who was born in June & July and interestingly she is over -6.00.

So what should you do?  The theory is that it is the increased amount of light in the summer months that may stimulate the development of severe myopia in 5% of the population.  So I would recommend ensuring your summer newborn has adequate protection(sunglasses, hats, shade) from bright sun in those first few months.

Michael D. Nelson, OD