One of those everyday astonishing things that we don’t much notice is the way that our brain merges the input from our two separate eyes into one indistinguishable image. This act is called fusion and for those who are doing it, it is as natural and unconscious as breathing. When we decide to give it some attention we can enhance and improve it and achieve some amazing effects on our visual system.
Fusion is the trait that gives human beings three-dimensional vision. It allows us to ‘see’ the difference in depth and perspective of objects and the world at different distances from us. Without fusion, our visual world is flat and two-dimensional.
For those who don’t have fusion, the brain very often does an amazing job of compensating for this, and there are many people who don’t have fusion and are not even aware of the lack. The brain is so good at guessing, extrapolating and estimating that they can almost have the effect of three-dimensional vision, but of course it takes a lot of energy for the visual system to do this and it will never be as effortless and accurate in depth perception as the vision possible when fusion is in place.
Fusion happens in the brain and it can be quite mysterious in its action….those with perfect vision can lack fusion, and those with quite poor eyesight including a difference between the two eyes may have it despite this. In some folks fusion comes and goes depending on where they are looking. The most common situation is one in which a person has a reasonable difference in acuity between their two eyes and the brain ‘switches off’ the image from the blurrier eye.
When we regain and improve our fusion, it gives an exciting experience; depth perception can be almost psychedelic for those regaining it after a period of absence. It usually offers increased clarity and detail perception as the brain is doing what it was designed for in using the images from both eyes together. Fusion activities are the thing that can improve already ‘normal’ vision to better than normal, and it is an enjoyable and enhancing activity for all types of refractive error.
To discover if you have fusion we use a simple assessment called the Gate, as outlined in this video:
More detailed fusion activities are available in our book
Those who have the Gate can go on to further levels of fusion activity such as the circles and rosebushes chart in our book and kits, home-made fusion charts using postage stamps, hand drawn images, and Magic Eye®pictures.
Those who lack fusion may need to do some patching and vision activities to improve the vision in their blurrier eye. If the eyes are pretty much at the same level and there is still no fusion, using ‘the Fantastic Fusion Fixer’ card (as in the Practical Guide to Natural Vision Improvement book) can be very helpful. When improving eyesight, at the first sign of double vision, fusion games must be begun and practised regularly. In this situation the double vision indicates the brain has started to use the images from both eyes and they must be brought together with these specific activities.
Below is a fun way to practice and enhance fusion for those who do have the Gate, using a homemade fusion chart.
Obtain postage or similar stamps with beautiful natural pictures on them. Ideal are those with landscape, flower, or animal pictures with both a foreground and a background. You could also use stickers in the same way. Choose images you will enjoy looking at. Purchase two of each image you wish to use.
Take a piece of cardboard or construction paper, preferably black or dark blue. For easiest fusion, place two identical stamps on the card next to each other with the edges touching.
Hold the card at a comfortable distance, as you would for reading. The goal is to obtain an image of three stamps from the two stamps, then bring the middle one into focus. The centre stamp is the fused image. There are number of different ways to achieve this.
One way is to ‘unfocus’ your gaze on the card itself until you see three blurry stamps. Then bring the centre stamp back into focus as much as possible. It’s hard to describe how to do this, it’s a matter of playing around with your brain and eyes until you get it. Remember that if you have blur at this distance than you will still have blur when you have fused the images, but hopefully the centre stamp will appear different from the outside two.
Another way is to allow your visual attention to go beyond the page. (Holding your pencil or hand 15cm (6 inches) behind the page may help.) For some it will work better to bring the visual attention in front of the page. (Hold your pencil or hand between yourself and the page, play around with different distances and see what works.) Either way you will see the three stamps in your peripheral vision. Holding the image of the three, bring your gaze back to the card so you can look at and clarify the centre stamp.
Remember that it is always important to breathe and blink. In fact sometimes a spate of rapid blinking may help to bring a fused image into place.
- Once you have gotten the fused image, play around with it to see how clear and sharp you can make that centre stamp.
- Remember the two outside stamps will always remain blurry.
- You can make more advanced pairs by placing the stamps slightly apart. Increase the distance between them to increase the challenge.
- You can also ‘trombone’ the card, bringing it towards and away from you and seeing how well you can maintain the fusion and sharpness of the image.
- Try it out with different sized stickers and stamps too!