This past August, I had eye surgery, an event giving me a renewed appreciation for what our brains are capable of, and their elasticity in accommodating and assimilating sensory input as well as ideas. My recovery reminded me of the film shown in many classes in the 1960s, where a researcher wore a set of glasses that caused the world to appear upside down. Within a few days, the researcher’s brain inverted the image and the world once again appeared right side up. A couple of days later the glasses came off, and everything again was upside down, and eventually the researcher again perceived the world as before the experiment. It takes babies several weeks for their brains to learn how to fuse the inputs from each eye into a single image.

In my case, a defect in my eye muscles caused them to not work properly, creating a misalignment of my eyes. The misalignment was great enough that my brain couldn’t compensate for the difference, resulting in some double vision. Minor surgery was successful at correcting my muscular imbalance, aligning my eyes so my brain is able to fuse the input from both eyes into a single image. But the fusing of these images following surgery was not instantaneous, and took several weeks for my brain to relearn how to see and completely restore my singular perception of the world. As with babies, the ability to track moving objects took longer to redevelop.

The restoration of my sight is somewhat analogous to what educators do when confronted with a learner’s lack of understanding, and perhaps misconception of scientific principles and/or natural phenomena.

An in depth understanding, and ability to thoroughly explain phenomena requires time and multiple opportunities to practice, with sustained contact with the concept over many days if not weeks. As with any learner, effective teacher professional development related to natural phenomena should include reinforcement over time.

In the case of solar and lunar eclipses, one could show someone a diagram and explain the phenomena in words, which a learner could, in all likelihood recite verbatim back to the explainer. However, really owning the concept through cognitive accommodation and assimilation takes time and an awareness of a suite of background concepts and phenomena including: Earth’s (and the Moon’s) rotation and revolution, and their relationship to how time is measured; shadows and light, particularly the kind of shadow cast by a spherical object illuminated by a single, point source; the measurement of angular size; size and distance scale of the Earth and Moon; the frequency and pattern of lunar phases; and the frequency and pattern of lunar and solar eclipses, and their relationship to lunar phases. The learning of any one aspect of eclipse phenomena is akin to keeping one eye closed when looking at a distant object. The depth of understanding is lost, much as binocular vision is necessary for visual depth perception. A misconception, such as lunar phases are the Moon passing into Earth’s shadow, or the Moon really is larger when it rises is similar to having both eyes open but with each eye gazing in a slightly different direction. The brain may pay greater attention to one image while relegating the other as an annoyance safely ignored. Unfortunately, many misconceptions offer a stronger, and perhaps more intuitive appeal, until the learner is confronted with evidence with which to dispel the misconception. It is in the fusing of all the experiences where in-depth learning and integration of a concept takes place.

As mentioned in previous Education Matters columns, the Next Generation Science Standards have provided a marvelous framework for engaging learners in the sorts of in-depth investigations necessary for fully understanding eclipses. Through the use of a storyline approach, educators can actively engage learners in each of the essential background concepts mentioned above. Using resources developed for ASP programs the Night Sky Network, Project ASTRO, and Astronomy from the Ground Up, ASP staff have created such a storyline and are using it in workshops to help educators prepare for next year.

The total solar eclipse on August 21, 2017 is a teachable moment without compare. Taking place mid-day, on a day when many schools throughout the country are in session, it is an opportunity for educators, in and out of the classroom, to engage learners of all ages in experiences with both eyes open, both literally and metaphorically, promoting a full understanding of a phenomena that has caused wonder and bafflement for millennia.

This post originally appeared as the Education Matters column in the fall 2016 issue of the ASP’s Mercury magazine.