I have osteogenesis imperfecta, the brittle-bone condition that the super-villain Mr. Glass (Samuel L. Jackson) has in M. Night Shyamalan’s movie “Glass,” which opens Friday. Mr. Glass is so named because this genetic condition makes his bones exceptionally fragile. This rare disability is also in the spotlight in the History Channel’s “Vikings,” where antagonist Ivar the Boneless goes to war with his brothers and declares himself a god.

These portrayals leave me conflicted: They bring visibility to a condition most are unfamiliar with, yes — but that introduction is painted in a starkly negative light, reinforcing an idea that physical flaws, ailments or disabilities are connected to moral failings. “Glass” even doubles down on this idea, pairing Mr. Glass with Kevin Wendell Crumb (James McAvoy), who has multiple personality disorder.

Over the past few years, movements such as #MeToo and Black Lives Matter have been successful in shining a light on our cultural blind spots and failings as a society when dealing with issues of race, gender and sexual orientation. They facilitate difficult but pivotal conversations that reframe the ways we think and speak. They reveal to us just how much we need to improve in order to live in a more equitable and mindful society.

The community around disabilities, however, remains largely marginalized. Those crucial conversations about language, perception and equal treatment are still rare, often an afterthought when discussing other minority issues. There hasn’t been a moment or a movement on the scale that other communities have had in recent years. As a result, frequent typecasting as victims and villains or monsters, objects of pity or scorn, can pass through the public eye with much less commentary.

Why might this be? Perhaps we in the disability community simply lack the numbers, but this is unlikely. (The Census Bureau documented nearly 40 million Americans with disabilities in 2015.) Alternately, there is such diversity in the exact nature of disabilities and the impact they have on individuals’ lives that it limits the capacity to see them as one group, or perhaps even limits solidarity and the capacity to band together.

Many disabilities limit one’s available energy, and that impinges on one’s ability to organize and advocate. I’ve sustained dozens of broken bones over the years, the vast majority before the age of 25. That takes its toll. I prioritize my career — I was teaching university courses via Skype four days after an extremely bad fall that broke eight bones in 2015 — but that limited my energy as well as other concerns (e.g., difficulty driving or walking long distances).

Some of my energy needs to be diverted to personal advocacy just to function. For instance, over the years, a number of security guards have insisted that I’m required to take a stair entrance when in a wheelchair, rather than the only ADA-compliant entrance. Fighting these little battles routinely can make it more difficult to fight the bigger, systemic ones — even if, ultimately, they’ll make the little ones unnecessary. But the typecasting and lack of a seminal movement may ultimately have little to do with such factors, and much more with how the broader population perceives and engages with disabilities.

Though Mr. Glass and Ivar the Boneless are both unquestionably villains, they are still portrayed as highly motivated and powerful characters. The perseverance and determination that they channel in pursuit of their ruthless goals were necessary qualities to overcome a lifetime of their bodies constantly breaking and rebuilding. Unable to compete physically with their peers, both honed their intellects. But these admirable qualities need to be turned just as often toward positive depictions, not only corrupted in purpose to serve as adversaries to more classically fit heroes.

With visibility, even in the form of flawed characters, comes the opportunity for discussion about how we see disabilities. It is a moment to focus on how we can make room for their portrayal in a balanced light, reflecting the human condition as a whole: the good as well as the bad.

Nik Sawe is a lecturer in Stanford University's Emmett Interdisciplinary Program in Environment and Resources, where he uses neuroimaging to study human decision-making in environmental issues.