Hey, [s2Get user_field=”first_name” /].
Today’s session is from the original, back-in-the-day course. It’s interesting at the very least, even if the application of it may or may not be always fully relevant to you as you progress with your eyesight.
Ready? Here we go:
So far we covered several environmental factors that impact your vision (major ones being lighting conditions and close-up strain).
As you continue to build on your task-dependent use of prescriptions, we want to look at other factors that affect your vision.
Chiefly among these factors that affect your eyesight, is ambient velocity. You may have noticed this already – if you are wearing your normalized prescription while taking a walk, objects may appear to be clearly defined. But, when you are moving at higher speeds (driving, riding a bike, on a bus), you feel as though the prescription is not strong enough.
You may or may not have consciously experienced this. Next time you have the opportunity, compare walking and driving, while wearing your normalized prescription. Note whether higher velocity affects you (subjectively) in terms of perceived clarity of your surroundings.
As we continue on the path of vision improvement, you will continue to gain a larger appreciation for just how much your eyesight is affected by your surroundings. I have quite a few interesting facts we will continue to explore that deal not only with the focusing ability that we are working on now, but also your brain’s role in processing the information projected onto your retinas.
The first an obvious implication about velocity is personal safety. If your normalized prescription makes it difficult to properly assess road conditions, read speed limit signs, engage peripheral vision, you want to use your previous normalized prescription for higher velocity tasks. In most common cases, your brain’s processing ability begins to be affected by about -0.25 diopters for a speed of about 30km/h. 60km/h adds another -0.25 diopters, for a total reduction of -0.50 diopters of perceived acuity loss at average commuting speeds.
Above is based on a study I had done some years ago with clients, average age of 34, six months into the program, at a starting average of -3.75 diopters and then current improvement to an average -2.25 diopters. They were all on their second normalized prescription, with a -0.25 diopter decrease, average five weeks into that prescription. They represent the median client, statistically.
If you vary significantly from above average, your experience might vary quite a bit.
Let’s take a look at how you can estimate your own vision impact by speed:
Use a street sign with only a few letters and 30cm or taller writing (just as a starting point, feel free to experiment). Find the standing distance where the sign still is at the edge of blur. Now, try the same while riding a bike past – consider, that this is of course a rough estimation. You may find though that you may have a difficult time reading the sign as you pass the standing-distance marker. You can try the same, while driving a car past.
While this is a rough estimation, and far less involved than my study on the matter, it still provides you with a reference on how much your vision is affected by velocity.
Why do we care about this?
Vision acuity affects much more of your perception of your environment than you are consciously aware of.
When we are standing still, there is more time for the ciliary muscle to focus. There is more light from the object hitting your retina, giving the brain more time and data to process. The faster you are moving, the more data has to be available to accurately process your surroundings – meaning, you need clearer vision to begin with, to still see clearly while moving quickly.
As you are working to improve your eyesight, these are things that will increasingly become important, and worth consciously experiencing. I like to point out these kind of mini experiments and conscious awareness exercises. They help you improve your vision much more than just focus pushing, focus pulling, and other static exercises. This is a three dimensional experience, and your awareness and appreciation (!) of it helps you continue to improve. There is a significant intangible value in not merely following exercises in a ‘robot’ type of fashion. Awareness adds to your rate of improvement, I have found consistently over many years in this practice.
We will talk about peripheral vision, varying lighting conditions, and other factors as we continue this process of vision recovery. You have already experienced notable improvement – to keep up the pace, we need to continue to step out of the core routines to continue to feed stimulus to the whole system (not only your focusing muscle and eyeball physiology, but also the processing system – your brain).
It is by design that we start with the ‘low hanging fruit’ and simple, tangible work in the program, and then slowly move into some of the more abstract and intangible aspects. Now that you already know you can improve, we eliminated the internal scepticism. You can now enjoy some of the more unusual experience, such as how your vision might be affected by something seemingly unrelated – like your own velocity.
Things you can do today:
1. Find a good experiment road sign (as described above).
2. Compare static / below 10km/h / above 20km/h speeds acuity.
3. Add your experience to your log, repeat next month, compare results.
As we work our way through lowering your prescriptions further, I will continue to introduce new practices and opportunities for observation. If you would like to add your own insights, please do take a moment to bring them to the forum.
I include this session even though it’s from the old course, because it highlights the “processing” work that happens in your visual cortex. Whenever you are at the edge of clear vision, when you are pushing for better results, the system as a whole is challenged. A bit like your computer might, you notice a little bit of “slow down” in the processing when this happens.
Chalk it up to additional awareness and appreciation, as you go along with these sessions.
Next we’ll talk about plateaus, and more on the topic of centimeter improvements.