Video Transcript:
Hi, I'm Charlie Saccarelli, and today we're going to talk about Aniseikonia. Aniseikonia is the size difference between two eyes. So, picture that you see one thing this size and then one thing this size. Your eyes are essentially trying to make those two equal. And the effort to make those two equal can be a lot.
It can be very challenging for some patients. When we think of Aniseikonia and how it affects vision, there's different levels and different challenges of Aniseikonia. One of the biggest challenges is that normally the source of the Aniseikonia is a difference in refraction. When you go to the eye doctor, you have two eyes and they refract each eye individually. When one of your eyes is much different than the other, when we make you a pair of glasses, the glasses are going to produce different image sizes. Now your ability to deal with image sizes, being a little bit different, you have a pretty good ability to do that. What the problem ends up being much of the time is a kind of similar condition or it's a condition that exists together, and that condition is and is called Anisometropia.
Sorry for the big word, but what Anisometropia is, is that when we look through the center, everything's cool. But as we look off center the images, because of the refractive difference, the images move at different rates and the moving at different rates creates a discomfort, and the further you go, the worse it is.
Now, along a horizontal plane, a lot of the time this isn't too much of an issue. Your eyes are very resilient and very good at dealing with issues along the horizontal plane. Where we really notice the impact of Anisometropia is vertically, because a lot of people would be looking, say, through the top of the glasses to view.
If you're driving, you would be viewing the top of the glasses, and then you would be looking through the bottom of the glasses to read. So, then maybe for your computer, you would be looking at the middle of the glasses. Each one of those circumstances, usually with the lens, there's just one kind of sweet spot that we call the optical center.
In that sweet spot, everything's pretty cool, but then when you move away from the sweet spot, up or down, you experience potential discomfort. So dealing with the different tracking of the images is the biggest challenge with Aniseikonia, and the best way that we've found to do that is with freeform optics and a design strategy used by a company called Shaw Lens.
What Shaw lens does is look at the prescription difference. When you look at the prescription difference, you can predict and calculate mathematically what the problem will be. So if I plug in a certain number of parameters that are common measurements that I can take from your face, your glasses, the prescription itself, what we can do is calculate and design a lens that is ideally suited for the different positions of view.
The bigger the differences between the two prescriptions, the more pronounced the effect is. One of the things I always think about is how resilient and powerful our brains are at making things work. But then the question is how much effort? How much brain effort is it taking to make things work? If you have a difference between your prescriptions, you might not notice something that you would quantify as “Hey, I'm having trouble reconciling the two images in my brain.”
What you would say is, “Man, I'm really tired around 2:00.” When we are dealing with that stuff, the symptoms are very subtle. They might not be subtle per se, but they're symptoms that you wouldn't necessarily associate with your vision. So headaches and tiredness and just kind of general exhaustion when you're doing the tasks where your eye imbalance is most obvious.
When we're thinking about how Aniseikonia affects vision, you looking out of your eyeballs are probably not going to go into the doctor complaining about how we think of Aniseikonia. The way that we think of Aniseikonia is: okay, you have two different image sizes, but that's not going to be your complaint. Your complaint is going to be like, “Hey, my head hurts at 3:00.”
It's important to recognize that if you have these symptoms, exhaustion, that sort of thing, that it is important to look at your binocular vision and that most optometrists - the optometrists who, I would say, don't exceed the standard of care - those optometrists probably aren't going to be looking at your binocular vision as a potential source of your symptoms.
So, if you have a big difference between your two eyes, I would highly recommend talking to a binocular vision specialist. There's a lot of them. There's one group called the OVDRA. The other group is called Nora. They are all binocular vision specialists and will definitely be able to help you more than your standard department store optometrist.
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Disclaimer: The information provided in this video is for educational purposes only and is based on our experience in optical solutions. We are not medical doctors. Consult with your ophthalmologist, neurologist, or other qualified healthcare professional before making any changes to your treatment plan. The solutions discussed are intended to support, not replace, professional medical advice.