Last summer, my partner and I signed a lease on a new apartment on the third floor of a brownstone in Harlem, across from the Pentecostal Assembly and a bodega with dusty bottles of Fanta in the window. We thought little of the fact that the building was a walkup—we were young and able-bodied and joked that now we wouldn’t need a gym membership. But in the two months that passed between the signing of our lease and the arrival of our move-in date I developed an autoimmune disease that left me unable to walk. It started with sporadic, increasingly intolerable spells of joint pain, which began in one shoulder and spread symmetrically to my wrists, ankles, and knees, until one morning I woke and could not lift myself out of bed. On June 1st, we arrived at our new place with my partner pushing me in a wheelchair. We left it in the entryway, where I sat down on the stairs and then slid up the three flights backward on my butt.

The irony of my dependency on the chair, I mused, was that disability had always been more than a merely intellectual interest of mine. For years, I had volunteered with the Special Olympics, worked at multiple summer camps for kids with disabilities, and served as a classroom aide at a school for the blind. And yet I was the “normal” kid in my family. At the age of five, I had watched as my two-year-old brother, Matthew, lapsed into silence and stopped making eye contact. He lost words: “dog,” “light,” “shoe.” He lost our names. I pictured his words as glass beads on a string, which he released one or two at a time and then spilled all at once. He developed violent tics, along with obsessive behaviors—like shredding toilet paper into tiny flakes, then jumping up and down with a shriek as he watched them drift to the bottom of the staircase—compulsive vomiting, and seizures. His only hobby was watching Disney movies—“Peter Pan,” “The Little Mermaid,” and so on—on rewind. As the years wore on, with no interventions availing, it became clear to us that Matthew would never attain the goal that so many special-education programs and social-service agencies had pushed him toward since childhood: that of an independent life.

Perhaps it was partly in search of such a life, and in reaction to my brother’s confinement in a series of what we no longer call institutions, that I exiled myself to Siberia after college and toyed with the idea of a career in the foreign service. When, upon returning to the U.S., I decided to undergo a gender transition, it felt like the culmination of years of unspoken identity crisis; it felt like the first thing I had ever done completely for myself. In hindsight, I realize that I had always seen my brother’s body as a precarious and unknowable foil for my own, and I cannot disentangle my own act of claiming agency over my body from years of witnessing the porousness of his body’s boundaries. As a teen-ager, I had watched nurses restrain his spastic limbs; in college, I discovered a host of unaccountable bruises on his chest and neck after he spent the night at his first group home. It became clear to me that no legislation, no advocacy, was sufficient to protect him when he could not defend himself. Matthew never complained; he never said anything. I, meanwhile, sought to be independent enough for both of us.

One of the surprises of becoming disabled as an adult is that extreme incapacity is quickly followed by extreme overscheduling. In the six weeks that followed the onset of my symptoms, I became a full-time patient, wheeled from blood lab to doctor’s office to pharmacy, balancing a cell phone against my ear with one hand as I steered with the other, arguing with insurance providers and specialty-pharmacy technicians until I knew their hold music by heart. The diagnosis of psoriatic arthritis—which is incurable but treatable with medication—brought a glum sense of relief. But, as drug after drug failed to relieve my symptoms, I found myself adjusting to a life of chronic pain and fatigue. It wasn’t until my reduced-fare subway pass arrived in the mail, bearing the word “DISABILITY” in letters larger than the photo of my steroid-bloated face, that I realized this term might apply to me.

The term “disability” suggests a fraught relationship between the person it describes and the objects and institutions through which he or she must navigate. For the wheelchair-bound person, a cobblestone street can prove as impassable as a lava-filled canyon. To be disabled thus suggests dependency on a system of “special” accommodations, and to be marked “disabled” is to feel one’s sphere of action constrict, as everyday tasks take longer and become more difficult or simply impossible. It is to be simultaneously ogled and overlooked, as when a barista stared at me and then pointedly asked my partner, who was pushing my chair, “Can I get you anything?” Is there a way to think of this as something other than loss, diminishment, a newly small world?

Garrett Zevgetis’s new documentary, “Best and Most Beautiful Things,” tackles this question with sensitivity and verve. The film’s protagonist, Michelle Smith, is a bright, outgoing, quirky, and determined twenty-year-old woman; she is also legally blind and has Asperger’s syndrome. “I want to live on my own,” she says. “I want to see what the world has to offer: the good, the bad, and the ugly. The uncensored world.” Although she is on the opposite end of the autism spectrum from my brother, she faces similarly formidable challenges in her quest “to experience all aspects of life.” The film chronicles the two-year period after Michelle’s graduation from the Perkins School for the Blind, and shows how her disabilities compound the trials faced by so many millennials in search of work opportunities and meaningful relationships. As the camera work emphasizes through alternating crisp focus and strategic blur, Michelle’s sphere of attention is indeed delimited differently from most people’s. In order to read a Web page, she must keep her face so close to the screen that it looks as if she were about to nuzzle or taste it; in order to read a line of text, she must move her whole head. Michelle’s case seems to illustrate the notion that disability shrinks one’s world: “I got a job . . . and then I got fired from it,” she says, “and I pretty much spent an entire year in my room.”

The film informs us that seventy-five per cent of blind people in the U.S. are unemployed, and it shows that the most pervasive obstacles to their achievements can often be more mundane than people who are not disabled might imagine. Michelle has the cognitive competencies required for many skilled jobs, and yet just crossing the street to the bus stop is a daunting prospect. When Michelle spends an agonizing three minutes of screen time searching for her backpack in order to leave the house, amid her mother’s reminders that “we really gotta go,” every object on her bedroom floor seems like a roadblock to her success. She rifles through the debris and then, staving off a meltdown, plops on the edge of her bed in resignation and quips, “This is my life.” It seems clearheaded rather than ungenerous when her mother admits, “It’s going to be really hard for Michelle to find a job she’s able to do” in their home town of Bangor, Maine. “And I don’t think there’s going to be a lot of employers that are going to give her the chance.”

In a society where productivity is the measure of success, and the perceived value of one’s life too often depends on the size of one’s salary, a young person like Michelle must find or forge new models of an adult life well spent. My parents and I faced this realization in 2007, as Matthew, then seventeen, inexorably approached age twenty-two—the cutoff point by which the Department of Developmental Services mandates that all individuals with disabilities secure funding and any necessary subsidized housing and medical care. Matthew’s day program, funded by our local school district, had offered vocational training; on his twenty-second birthday, his funding source would shift from the district level to the state level, and if he did not qualify for the highest tier of D.D.S. funding—which offers residential care to severely disabled adults who both “require physical assistance” for at least three “Activities of Daily Living” and “present behavioral challenges”—he would need to find a job.

Like Michelle, whose anxiety proves too much for her supervisors at the post office hub to handle, my brother has behavioral issues that outweigh his abilities on the job. When hired as a server in a school cafeteria, he grudgingly donned a hairnet, only to turn around and vomit at the first sight of creamed corn. (“Can you blame him?” my mother asked the appalled vocational coördinator.) On his first and last day as a dog walker, he allowed a motley pack of canines to drag him to the curb, and then abruptly dropped all of their leashes and stood hooting with laughter as the Rottweilers and Labradoodles ran across the intersection, barking and wagging, with leashes bobbing behind them. Even after he had secured a job in the stockroom at T. J. Maxx, my brother seemed not to feel anything when he deposited his paychecks into the A.T.M. He would do the work, but he had no concept of money.

Ultimately, Matthew did end up receiving Tier II funding, which entitled him to full-time residential care as an adult. The transition-planning process begins at age sixteen, but it wasn’t until four months before his twenty-second birthday that we learned that the state would support him, to the tune of more than ninety thousand dollars per year. We moved him out of another group home and into a “lifesharing” program in the Berkshires, run by devotees of the esotericist and social reformer Rudolf Steiner. Matthew, whose transition to residential care was chronicled in a Times Magazine story, in 2014, is calmer and more secure these days, but his world is also smaller than ever. Many of the skills that were drilled into him in school have fallen away. However, his life now seems to revolve around things that matter to him. He does not earn any money, but he does take care of livestock, help around the house, and go swimming every day—one of his favorite activities. Limiting the scope of his environment has broadened the range of ways he can contribute to it on his own.

By the end of “Best and Most Beautiful Things,” Michelle has not found her dream job; her story suggests that higher-functioning people with disabilities may have a harder time in this regard than those who, like my brother, receive more financial support from the state. However, Michelle finds a way to turn the “small world” of the computer screen into a real-life network of peers. She becomes involved in the B.D.S.M. community online, and through this virtual interest she feels empowered to revisit the positions of subjection and infantilization that have disempowered her in the past, and to reclaim them as an agent—by, as she puts it, choosing her own “master.” Michelle’s mother fears that her daughter may be fetishized or even molested by others in the B.D.S.M. community, but Michelle remains secure in who she is and what she wants. Her relationship to B.D.S.M. gives her the confidence to move beyond the confines of her bedroom and, in her words, “to write and be an activist for women’s rights, for L.G.B.T., and for kink awareness and sex positivity.” The sighted movie audience, which watches her jump into a pool alongside her devoted boyfriend, and, later, give a speech about “Unlearning Normal” at the Bangor Pride Festival, cannot help but marvel at how all those hours alone in front of the screen have been a means to an end: she has managed to find a place for herself in the real world, and to express an inner life more complex and colorful than many assumed she was capable of.

My own, short experience of disability has already proved that not all solitude, and not all disenfranchisement, can be recuperated in this way. Sometimes, a loss is just a loss. At this point, I have mostly ditched the wheelchair; however, almost a year after my diagnosis, I still take a daily battery of pills and injections. I still walk with a cane or a walker. I have kept my academic job, but I have not received any additional, disability-related accommodations from it. On the far side of so many milestones of independence—travel, graduate program, job, apartment—I am relearning dependency. It is hard not to dwell on the uncertainties of my own future, but disability impels me to focus on my immediate physical environment. Before I can agonize over obstacles down the road, I first need to get where I’m going. My staircase, still so daunting in three dimensions, has become a serviceable metaphor for that. I grip the trusty bannister. I am thinking about the next step.