Question: I have a hidden disability that can flare up unexpectedly and make me dizzy or send me streaking for the bathroom. It’s mostly controllable by medication, which I use for on-campus job interviews.

Do I have to tell possible employers about it? I would like to be honest and brag that I’ve still managed to get a Ph.D., publications, and a teaching award, despite my disability. But I also know about prejudices. Should I try to pass as “nondisabled”?

Answer: Ms. Mentor has a dream—that one day all campuses will feature a rainbow of people moving easily through wide hallways for wheelchairs, finding sensor-equipped bathroom fixtures, using computers adapted for voices as well as fingers … and proclaiming a community attitude that everyone is welcome.

But such a utopia is far away. The Americans With Disabilities Act, passed in 1990 has helped get parking spaces, better bathrooms, ramps, and many other “reasonable accommodations” for disabled people and yet….

The bitter truth is that it probably will be much easier for you to get hired if you hide your disability.

Most people, including academics, think disability is rare, but it’s not. According to data from the U.S. Census Bureau, a fifth of Americans are people with disabilities. They are the nation’s largest minority group, and anyone can join in a minute. All it takes is a bad fall in the shower, or one drunk driver, and you’re a lifetime member.

Another myth is that differently abled or physically challenged workers are “too costly.” In fact, says a recent Cornell University study, most workplace improvements take only a little thought and a few dollars: phone headsets, easy-to-use software, desk rearrangements. Academe, with its movable schedules and student helpers and online courses, is ideal for people with deafness and other disabilities to share their knowledge.

But the big barrier, the Cornell study shows, is attitude— fear and loathing. Only people who really care will do the right thing, like the very poor rural African Americans, a century ago, who began training their blind children in music. Their success stories include Clarence Carter, the Blind Boys of Alabama, and Ray Charles. “Too costly” is really about a rigid and stingy perception of who is worthy and who is not.

Ms. Mentor calls it a very Puritan belief—the idea that if you’re not perfectly able, it is somehow your fault, and you deserve to be punished. (You didn’t wear your seatbelt, or you devoured a Whopper and enjoyed it.) In various pockets of righteousness around the United States, Ms. Mentor’s loyal readers have been scolded by strangers for eating meat or enjoying a beer. A judgmental tone has even crept into celebrities’ lives. When actress Maureen Stapleton died recently of lung disease, the obituaries all said that she was a smoker—making the moral very clear.

Those with visible disabilities, what Rosemarie Garland Thompson calls “extraordinary bodies,” know about being stared at, stigmatized, patronized, and denied insurance. But even the most virtuous, careful, and luckily insured Americans may have secret disabilities, such as migraines, asthma, allergies, or epilepsy.

For job interviews, they’ll pack their inhalers, pills, canes, and sun hats—and hope they won’t have to use them in public and be outed and seen as vulnerable. Too many job ads ask for “dynamic and energetic” people—which translates, Ms. Mentor knows, into “young” and “able-bodied.” Where is the acknowledgment that brilliant minds can come in all kinds of packages?

That doesn’t happen at many a hiring meeting, according to Ms. Mentor’s spies. More often, there are comments like, “Can Dr. Blind handle the reading load?” Or “Maybe Dr. Chair would rather be at a more accessible campus?” Or “Dr. Odd’s clearly got some kind of obsessive-compulsive disorder.” All such comments are illegal and bigoted, but they do affect hiring decisions.

Which is why Ms. Mentor admits this sad truth: that people who “pass” are more apt to get jobs. She knows heroic faculty members who have concealed their dialysis, their chemotherapy, and their prosthetic limbs, until after they were taken seriously for their intellectual achievements. And she knows that outraged readers will say she’s promoting dishonesty (“Take me as I am”). Perhaps she is, in an end-justifies-the-means kind of way. She would rather have people with disabilities able to bore from within, sharing their deep sensitivity and their great knowledge, than languishing, unemployed, on the outside.

Are there exceptions, people who’ve always been “out?” James M. Lang, for one, did not consult Ms. Mentor when he wrote his first book about his own disability (Learning Sickness: A Year With Crohn’s Disease). After his second book, Life on the Tenure Track: Lessons From the First Year, also appeared, he won tenure at Assumption College, where he’ll be able to share his insights for the rest of his teaching life.

Ms. Mentor lauds Assumption College and James Lang, and urges hiring committees not to look for oddities in candidates — such as twitches, limps, or eyestrain — and to be wary of the mind-set described by Lennard J. Davis: “We live in a world of norms.” Being “normal” or ordinary should never be a goal of education.

Ms. Mentor prefers teachers and students to be unique and extraordinary, to be leaders in a world where people can sashay, limp, or wheel themselves about—keeping pace with the slowest and helping them along. We will all be disabled eventually, if we do not die first. People with disabilities may have to conceal their vulnerabilities for now, but not when there are enough of them, and enough people with open hearts and minds.

Ms. Mentor knows we could all use more of those.