Neuroadaptation - Updating the Brain for New Vision
Matthew Caldwell, MD
When I was in college, I realized I wasn’t seeing very clearly, and I was prescribed my first pair of glasses.
I immediately saw more sharply, but I didn’t love the glasses or the vision. Specifically, the edges of the lenses bothered me. Whenever I looked to the side, especially checking my blind spot while driving, I saw the lens edge and noticed a slight image shift. It kind of drove me crazy.
However, I kept wearing the glasses because I wanted clear vision. Over the course of a few months, I noticed it less and less, until eventually I no longer saw it. If I tried, I could find it, but my brain didn’t otherwise register it.
This is because of the wonderful phenomenon of neuroadaptation. Neuroadaptation refers to changes that occur in our brains as they learn to make sense of new sensory information. This process is active from the beginning of life and is important to just about all areas of our perception of the world around us.
Our brains are continuously bombarded with myriad stimuli not only for vision, but numerous sensory nerves all over our bodies detecting things like pressure, hot, cold, vibration, pain, smells, sound, position, and balance.
In the case of vision, our eyes provide the optics to collect visual information, but ultimately, it is our brain that does the seeing. Our brains do a tremendous amount of work in processing and making sense of the visual information that our eyes collect. Neuroadaptation is vital as we experience changes in vision, allowing our brains to adjust to new information.
Our brains are programmed to detect change, and ideally to focus on what is important and to ignore the rest. When you sit down, you feel the pressure of the chair against your body, but the prominence of that information is quickly pushed to the back of your consciousness to make room for more important things.
Continual stimuli, when determined to be unimportant, are pushed out of our awareness. If we intentionally think about them, we can still detect them, but otherwise, we don’t notice them anymore.
A change in the optics of the eye is very noticeable at first. That is normal. It is a good thing. Our brains are programmed to learn what is important from that change, and then gradually adjust and downregulate the aspects that are not needed, so we can focus on what is important. We adjust to a new baseline.
This is often noticeable when getting a new prescription for glasses. Similarly, after cataract surgery, vision is initially much brighter, often with a blue hue relative to the yellow discoloration we got used to seeing through cataracts. The way light focuses is different with a prosthetic lens, especially with multifocal and expanded depth of focus lenses. This is very noticeable at first, but becomes less so as the brain “recalibrates” to the new optics of the eye.
Some instances where our brains need to recalibrate to adapt to new vision include:
New prescription glasses
Bifocal and progressive lenses
Cataract surgery, especially with multifocal lenses
Monovision
Dysphotopsias
Floaters
We are all programmed a little differently. Some of us adjust to vision changes almost immediately, but some of us sometimes take longer. However, given time, almost everyone will adapt to changes in their vision.