How often do you think about your vision?
I don’t mean your “Vision” for your life, or how you want the world to be. We’ll get to that later this week.
For now, I am referring to your literal vision. The work your eyes do that enable you to see things around you. The act of seeing.
Unless you have problems with your vision, you probably don’t think about it much.
Adjusting to Near and Far, Dark and Light
Consider: right now you’re reading this. Possibly on a computer screen, more likely on a tablet or phone. The screen is probably close to your eyes. Pause and look up. Look around. If there’s a sign with writing nearby look at it. Let your eyes focus on something farther away than your screen, then come back here.
Notice how you could look up, see the thing that was farther away, then look again at your screen and read these words.
Or consider how your pupils adjust to allow you to see in both light and darkness.
Processes We Rarely Think About
The ability to see things at varying distances is something that many people take for granted, until the time comes when they need distance glasses or reading glasses. Before that time, you may not even think twice about how your eyes adjust — without your interference — to see things close to you and far away.
I’ll save you the detour to Google. Here’s how
Just behind the pupil (the black hole in the center of your eye) and iris (the colored part of your eye), lies the crystalline lens, which is connected at its outer rim to the ciliary body by ligaments called zonules. The lens focuses light rays on the retina, the thin, light-sensitive inner layer at the rear of the eye. Muscles in the ciliary body enable the flexible lens to alter its shape and allow the eye to focus on objects at varying distances.
This process is called accommodation.
You might be more aware that your pupils constrict and dilate to adapt to light and darkness.
Even then, how often do you consider exactly what is happening as it happens?
For most people, the answer to both is: Not often, if at all, unless something in the process breaks down. Which makes sense, because you don’t need to think about it. Until you do.
The contraction and relaxation of the muscles involved in vision are some of the body’s many processes that happen without our conscious involvement.
This is a good thing, because we have enough to think about. Imagine if you had to actively engage the muscles of the ciliary body every time you shifted your gaze. You’d be exhausted before the day was half over.
But because we don’t have to think about activating these muscles, we rarely consider that we are using them all day long. In fact, the eyes are the most active of our sense organs. They work for us every moment that they are open.
Imagine if you were doing squats throughout the day with the same frequency. Hmm.. that gives me an idea for an interesting experiment: do a squat every time you adjust your focus. You’d probably want to rest your quads and glutes at some point. Also your brain would be exhausted.
Vision is hard work, even if you’re not thinking about it.
[…] This is part 2 in a series on vision. Read Part 1 here. […]