Amblyopia, or more commonly known as lazy eye, is a decrease in vision of the eye(s) without detectable health problem. There are two types of amblyopia: strabismic and refractive. Strabismic amblyopia is when there is a problem in our binocular vision (how well your eyes can work together). When the two eyes are not directed simultaneously to look at an object that a person is looking at, then only one eye will receive information about what it is seeing. The other eye decides to be “lazy” and starts to move in any direction it thinks is comfortable. This lazy eye creates what optometrists call a strabismus (a misalignment due to muscle imbalance in the eyes). This becomes a real problem for younger kids because they are still growing and so are their eyes. With one eye hanging off to the side and doing its own thing, there won’t be normal visual development.
Another reason why a person could amblyopia is because a person has a very large difference in prescription between both eyes. This is called a refractive amblyopia. In these situations, people can normally keep their eyes lined up and pointing in the right direction. Of course, this isn’t your typical lazy eye appearance, the real problem is happening behind the scenes. Often a person who has amblyopia due to prescription differences suppresses an eye. Suppression is fancy eye doctor terminology for the brain blocking out the vision coming in from one eye and relying only on the other eye. Basically, you think you’re seeing out of both eyes, but your brain is only using one. This becomes a problem for a patient’s depth perception. We need both of our eyes to give us the binocular vision required to see depth.
Now you might be wondering how in the world do optometrist’s treat this condition. There are a couple options out there! For both types of amblyopia eye doctors offer vision therapy or VT for short. These appointments will consist of a series of exercises that will help you to work out those muscles in your eye to strengthen them. After the appointment you will often be assigned with homework (I know who does homework anymore?? But I promise it will all pay off in the end!). These assignments are usually just a repeat of what you did with the doctor so you can exercise your muscles on your own time.
For strabismic amblyopia there are a couple more options out there. If vision therapy is not for you and all you want are glasses, optometrists can prescribe prism in your glasses. (Warning! This next part is a long explanation of the physics of prisms. So, if you don’t care about the math that is disguised as science, skip ahead! I’ll let you know when to start reading again. ☺️) Prisms are optical devices that help shift your visual perception. Prisms are shaped like pyramids, so just picture one in your head as you keep reading. At one end of the prism is the apex (the top of the pyramid) and the other end is the base (the bottom of the pyramid). Light that enters the prism (from the faces of the pyramid) gets refracted towards the apex. Basically, an image in your visual field will get shifted to the apex of the prism. This will also move your eye because it will follow the image that the prism has shifted. To put this in perspective, let’s say your right eye is swinging out to the side. We want the eye that is sitting out to move inwards. When we place a prism (base out in this case) in front of that eye, it will send the image inwards, towards the nose, and the eye will also swing back towards the nose.
(End of unnecessarily long basic science explanation for the nerds like me! Continue reading from here please!)
With the prism in place it will help with the cosmetic appearance of your eyes by helping them look a little more aligned. The other option is surgery. This is more of a last resort option if VT or the prisms are not the ideal choice for you. In the event you would like surgery an eye doctor can refer you out to an ophthalmologist that specializes in strabismic surgery.
Now for refractive amblyopia, the treatment options are a little simpler. Our first option is vision therapy of course but the other options (and a lot of you out there might like to hear this) is contact lens! Yes, as optometrists we do encourage contact lens wear as long as you are responsible with them. Contact lens are a great option for a few reasons. With a large difference in prescription between the eyes there will be a cosmetic effect on our eyes when wearing glasses. Patients that are higher myopes (nearsighted) are prescribed lenses that will make their eyes look smaller to other people. Patients that are higher hyperopes (farsighted) are prescribed lenses that will make their eyes appear larger. With contact lenses there, we can eliminate the magnification difference and enhance the cosmesis effect for the patient. The other benefit for contact lens is that any visual distortions from the lens in glasses will be eliminated. This includes the magnification difference when a patient is looking at an object and any other lens distortions in the periphery.
If you think you have amblyopia or if you know you have amblyopia and would like to talk more about these treatment options, contact your nearest optometrist! (Preferably Dr. Toader if you’re from the Chicagoland area because she also offers vision therapy at her office! ☺️)