My eye doctor prescribed spending time outside

We have all heard about how much time kids spend inside watching TV, studying, and playing video games. My seven-year-old son is addicted to rainbow looms, and could loom all day if I let him. New studies have indicated that the amount of time children spend outside may decrease the risk of developing myopia.

What is myopia?

Myopia, or nearsightedness, is a vision condition in which close objects are seen clearly but far objects appear blurred. Nearsightedness is a very common vision condition, affecting nearly 30 percent of the US population, and up to 90 percent of developed East and Southeast Asian countries such as Singapore, Taiwan, China, Japan and Korea. Myopia typically presents in school age children. Because the eye continues to grow as children grow, myopia may progress until approximately age 21.

Photo Courtesy of Shirley Binn

Photo Courtesy of Shirley Binn

Recent studies have indicated that more time spent on near work, less time spent outdoors, higher educational level and parental history of nearsightedness are risk factors for developing nearsightedness. Spending time outdoors plays a crucial role in myopia development and can slow its progression.

A recent study presented at the Association for Research in Vision and Ophthalmology (ARVO) 2014 Annual Meeting demonstrated the importance of time spent outdoors in order to control nearsightedness. The study evaluated visual acuity (vision) and axial length (length of the eye) of 6690 multiethnic children at 6 years of age. Axial length was significantly longer in children who spent less than one hour per day outdoors than in those who spent more than 2 hours outdoors.
Jan Roelof Polling, at the University of Applied Sciences Utrecht, lead investigator of the study recommended “Children with an increased risk of near-sightedness, such as those from a near-sighted family, should be prompted to spend at least 15 hours a week outside and should avoid spending long hours doing near work, even when they are very young.”

Photo Courtesy of RavEytan

Photo Courtesy of RavEytan

How does spending time outdoors help with myopia progression?

The protective effect of being outdoors is not well understood. Researchers suspect that bright outdoor light helps children’s developing eyes maintain the correct distance between the lens and the retina, keeping vision in focus. The intensity and / or specific spectral distribution of outdoor lighting may be beneficial. Indoor lighting that is dim does not provide the same kind of feedback. Therefore, when children spend too many hours inside, their eyes fail to grow correctly and the distance between the lens and retina becomes too long, causing far-away objects to look blurry. Hormonal changes associated with outdoor activities may also be beneficial.

Encouraging children to spend more time outdoors can be a simple and cost-effective way to improve their vision and general health. Head outside and enjoy the summer! Just remember to keep spending time outside when school resumes.

Melissa Barnett, OD, FAAO

California Optometric Association

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What did my doctor just say? Common terms your eye doctor will use and what they mean

Courtesy of riekhavoc (caughtup?) on Flickr

Courtesy of riekhavoc (caughtup?) on Flickr

Have you ever felt like you were not quite sure what just happened at your optometrist’s office? It is difficult enough to answer the “which is better, one or two?” questions and then at the end of the exam to try and understand the doctor’s explanations with difficult optometry terms without secretly worrying that you might have said something wrong!

Hopefully this blog will help you better understand some of the more common terms we use in our examinations.

1) First of all, most comprehensive exams will include a detailed case history. The doctor will want to know your family medical and ocular (eye) history. Some terms you may hear include the most common eye diseases – cataracts, glaucoma and macular degeneration.

  • Cataract is the term used when the natural lens of your eye becomes cloudy, causing blurred and distorted vision.
  • Glaucoma is the eye disease that causes your eye to have excessively high pressure, which can lead to long-term damage of the nerve in the eye.
  • Macular degeneration is a disease that affects your central or straight ahead vision.

Not only will the optometrist ask you about a family history of any of these conditions, they will also assess your eye health and your possible risk for developing any of them.

2) Next, the optometrist will perform a refraction to get you the best possible glasses or contacts that will correct your vision.

  • A refraction is just the process of determining for each individual what are the best lenses to give you maximum visual clarity and comfort at both distance and near.
  • Myopia – nearsightedness or the ability to see better at near than at far.
  • Hyperopia or farsightedness, really means that it is more difficult to focus at near and at far distances.
  • Astigmatism: this refers to the shape of the front surface of the eye being more football shaped rather than basketball shaped.

3) There are a few terms you might hear specifically in an child’s exam.

  • Pursuits: slow, smooth eye tracking.
  • Saccades: fast reading eye tracking.
  • Accommodation: focusing.
  • Binocularity: the ability of the eyes to work together as a team.

4) Finally, there are some terms regarding glasses that it might help to define.

  • Progressive lenses are the kind of “no line bifocal” that you might hear about on TV. But, unlike a bifocal, where there are two areas of vision, near and far, progressives have an unlimited amount of areas as you look from distance to near in the lens.
  • Transition lenses are the kind that change to dark outside. They undergo an anti-reflective treatment, which eliminates all glare and allows for crisper vision, especially at night.

Hopefully, this quick explanation helps with some of the confusing terms in an eye exam. As for any others, always ask your optometrist to explain something that does not make sense.

~Lisa Weiss, OD, MEd, FCOVD
California Optometric Association
http://www.coavision.org

I have an astigmatism. What is that?

Courtesy of Greece Trip Admin on Flickr

Courtesy of Greece Trip Admin on Flickr

Astigmatism is a term used by optometrists to describe a prescription for one eye that needs two powers to bring it into focus. It is not a disease or something that will make you go blind, but it can make things blurry at distance and at near.
Most people are familiar with the terms “near-sighted” and “far-sighted.” In the eye care world we use the term “myopia” for near-sightedness and “hyperopia” or “hypermetropia” for far-sightedness. These terms are used to describe the power (+ or -) of the lens needed to make you see clearly.
If your prescription needs only one power to bring your eye into focus then you can think of it as being simple. So if your prescription has a number like -4.00, then you have simple myopia. Similarly, if you have a prescription of +2.25, then you have simple hyperopia.
If you have an astigmatism in your eye, then you have two powers that need to be corrected for you to see clearly. Having an astigmatism in your eye is our way of describing a compound prescription. Instead of just one simple power like we described earlier, there are two powers together. Depending on your prescription, you can have myopia with astigmatism or hyperopia with astigmatism.

Courtesy of Ciro Boro - photo on Flickr

Courtesy of Ciro Boro – photo on Flickr

A common example optometrists use to describe astigmatism to patients is the difference between a basketball and a football. A basketball is nice and round, and has only one curve for the entire ball. You can think of that curve as a lens power. A basketball is a good example of a simple prescription. A football, on the other hand, has two curves. This is like an eye that has two powers or an astigmatism.
Astigmatism is not an eye disease, but rather a term we optometrists use to describe a compound prescription in one eye. So don’t be alarmed if your optometrist tells you that you have some astigmatism in your eyes. You are not alone – I have an astigmatism in both of my eyes and I see extremely well!

~Ranjeet S. Bajwa, OD, FAAO
California Optometric Association
http://www.coavision.org