Many a time we have heard that adult amblyopia (or lazy eye) is untreatable. Children with amblyopia can be cured, but after the age of 10 it becomes difficult to cure the vision condition. If not treated before then, you’d get a pat on the back and a pair of shiny new glasses. Looks like you’re going to have to get used to life with a lazy eye.
That was a harsh send off and not a very optimistic one at that. But studies are coming very close to finding a treatment for amblyopia in adults. The University of Waterloo in Canada and Sun Yat-sen University in China have collaborated on finding a cure for lazy eye in adults, and may have found the key first step in treating this long-time incurable condition.
Development of Amblyopia in Children
Amblyopia happens in children because it is considered to be an eye development issue. Their vision doesn’t develop fully or properly in one eye, making it the weaker one.
When one eye becomes more focused than the other, the brain will start to ignore the weaker eye, favoring the stronger one. Think survival of the fittest, where eyes fight for the brain’s attention. The one that is strongest gets to keep growing, while the weaker one slowly worsens and sometimes becomes permanently visually impaired.
The reason amblyopia has been so affectionately nicknamed “lazy eye” is because it can also be caused by an ocular misalignment, where one or both eyes are turned inwards or outwards. This can cause your child to have double vision and prevents the eyes from focusing together. This is when the brain starts to ignore the weaker eye.
Amblyopia can be brought on by something obstructing the light from entering your child’s eye, such as cataracts or bleeding. However, these conditions are rare in infants and children.
In young children, amblyopia is not anything to worry about. About three out of 100 children will be affected. If caught and treated early, chances are, your child can successfully overcome their lazy eye.
In children it is normally treated by having them wear an eye patch, or some other sort of light blocker over the stronger eye, to force the brain to use and develop the weaker eye.
Though most children treated under the age of 10 have been seen positive results, a study showed that in children and teens ranging from ages 12 to 17, the success rate dropped to 27 percent. The reason for this discrepancy is because the brain is increasingly responsive to treatments before the age of 10.
Amblyopia in Adults
All right, so now you know how amblyopia happens in children, but that’s not much use to you since you’re no longer a child. So where does that leave you? Well, it used to leave you in the dark, literally and figuratively. But now hope is in the air for those with adult amblyopia.
Before we get to the big reveal, let’s try to understand adult onset amblyopia. Up until now we’ve been discussing amblyopia as a development issue. Well as an adult, your eyes are already developed, so what gives?
As it turns out it’s still a development issue, but one that may have not been caught during childhood. It is often caused by an imbalance in the eyes’ vision.
For example, if you are farsighted, it is possible that you are more farsighted in one eye than in the other. But if this goes undetected and you wear the same prescription in both eyes, this then poses a problem. Because it is not being corrected properly, the eye which is more farsighted may come to be ignored by the brain, and cause amblyopia.
Because this is a fairly rare occurrence, up until now, studies on amblyopia would scarcely focus on adult amblyopia. By the time someone turns 21, their vision is normally stabilized, making it incredibly difficult to retrain the brain to use the weaker eye.
Treatment for Adult Amblyopia
Now, because amblyopia is an issue with the brain and not the physical muscles of the eye, finding a cure becomes tricky. Saying our brains are complex is a severe understatement. Years and years of modern technology and bright scientists, and the brain continues to be one of the body’s most complicated organs.
The University of Waterloo and Sun Yat-sen University have been hard at work for all the adults with amblyopia who’ve been told that there was no cure. Though a cure has yet to be found, a method of temporarily improving vision in the lazy eye has been discovered.
Using transcranial direct current stimulation (tDCS) for 20 minutes, patients were found to have increased brain activity to intercept image information from the weaker eye. This in turn led the patients to be able to see low contrast patterns, which was a clear indication of increased vision.
Though the main problem with a lazy eye stems from the brain, strengthening it physically couldn’t hurt. Various video games are also available as a tool to improve vision in the weaker eye.
What is tDCS?
Transcranial direct current stimulation doesn’t sound as fun as playing Tetris on your smartphone, but it could be an essential way to get the brain going again and forcing it to work with both eyes in tandem.
tDCS is painless and non-intrusive. The device is placed on a patient’s head, which is a sort of hat with a chin strap, and then small electrical currents are sent to the brain to stimulate certain areas. In this case, the tDCS device would be sending small impulses to the visual cortex.
By doing so, the brain is shaken awake, increasing its ability to rewire itself. This further proves that amblyopia, though sternly connected to the brain’s visual interpretation development, can also be reset and reorganized using tDCS.
This is an inexpensive method as well as being portable.
A treatment for adult amblyopia may not be here just yet, but science is getting very close. This new discovery of using tDCS to stimulate the brain’s visual receptors will open doors to new advancements and hopefully a cure in the near future.