Graduate student Hamid Charkhkar uses a fluorescent microscope to examine neuronal cells at a lab at George Mason University. (Jeffrey MacMillan/For The Washington Post)

Hamid Charkhkar is developing technology to help the blind see and the disabled walk.

Originally from Iran, he has spent the past four years studying electrical and computer engineering at George Mason University, focusing on mapping brain signals — the type of research used to build devices that bypass retina damage to give blind people a sense of sight and send directions from amputees’ brains directly to robotic arms and legs.

But Charkhkar and thousands of other foreign-born graduate students in the Washington area are left wondering whether they’ll be able to stay in the country and use their skills after graduating. To do so, they must obtain one of a limited number of visas offered to highly skilled foreigners, usually those with degrees in science, technology, engineering and mathematics — known collectively as STEM.

Help may be on the way. Last week, a bipartisan Senate panel unveiled an 844-page bill that would give U.S. immigration policies their biggest makeover in a generation. Included in the massive proposal: much higher limits on the number of “high-tech visas,” officially called H-1B visas.

The legislation is likely to encounter opposition, but if it survives, up to 110,000 foreign workers, many of them graduates, could be granted temporary visas annually in the main part of the program. Over time, as many as 180,000 visas could be given out.

As of now, U.S. Citizenship and Immigration Services can hand out no more than 65,000 H-1Bs every year. This year, applications for those visas surpassed the cap in less than a week. Once that happens, the department resorts to a lottery system to determine which applications are approved and which are denied.

In addition, an extra 20,000 H-1Bs are currently reserved for foreigners with degrees — often in STEM — from U.S. universities. The bill would lift the limit for those with advanced degrees to 25,000.

Supporters say the changes are needed to provide the nation’s employers with the type of skilled workers they need to grow their businesses and to help kick start the country’s sluggish job market.

“These are serious needs, and we have this group of students that can help alleviate some of the shortage in STEM,” said Ken Shaw, director of graduate studies for mathematics and statistics at Georgetown University.

“We really need to find a way to make it easier for them to stay here to fill some of these needs in the economy,” he added.

Business leaders have urged lawmakers to endorse the proposed changes to the high-tech visas. They cite studies that show universities are not producing enough native-born graduates in STEM fields to meet demand for positions such as computer engineers, software developers and IT specialists. A recent study by researchers at Georgetown concluded that the country will have almost 800,000 openings in STEM fields by 2018, 250,000 more than the estimated number of American STEM graduates in five years.

New York Mayor Michael Bloomberg has gone so far as to say the nation’s immigration policies are a form of “national suicide,” in that current policies effectively turn away many foreign-born graduate STEM students.

But those who oppose raising the cap on the specialized visas vow to fight.

Related: Does the country actually face a severe STEM shortage?

They contend, among other points, that foreign workers take jobs that otherwise would go to American-born applicants. Researchers and lawmakers — from both sides of the partisan divide — also say that the lower wages often paid to foreign workers depress wages all around.

‘It’s unnerving, not knowing’

So Charkhkar waits. He and at least 8,000 foreign STEM graduate students in the Washington area likely won’t get an answer for months, as the legislation is debated in the Senate and then in the House.

“It’s unnerving, not knowing,” said Charkhkar, 30. “It was a huge investment to get a visa, move here and learn the language, and I would like to stay.”

Charkhkar isn’t the only one who stands to lose if he has to return to Iran. Under the current system, American universities and taxpayers invest in foreign graduate students in other ways beyond their education, paying some to teach undergraduates or providing other aid.

The percentages of foreign STEM graduate students at research universities in the Washington area are lower than the most recent national average, which for 2011 was 39 percent, according to figures available from the Education Department. Still, they play an important role. At George Mason, 22 percent of this year’s STEM graduate students are not U.S. citizens, a rate that has been rising. At Georgetown, the figure climbs to 25 percent, and at the University of Maryland, it’s 37 percent.

Most graduates, faculty members say, are in no hurry to return home with their degrees.

In fact, “nearly all of our international students are predisposed to want to stay here after graduation,” Shaw said.

The wage issue is one of the most contentious aspects of the H-1B visa debate.

Sen. Richard J. Durbin (D-Ill.), one of the so-called Gang of Eight that authored the legislation, urged his colleagues on the Senate panel to crack down on companies that employ a large number of skilled foreign workers.

Related: Start-ups handicapped by slow immigration system

The senators who authored the immigration overhaul try to address those concerns with a provision meant to bridge the gap between wages paid to H-1B workers and those paid to Americans in the same positions. The legislation would essentially raise the minimum pay for H-1B workers from its current level — the average of the lowest third of overall wages paid to all workers in their occupation — to two-thirds of the average paid for their position.

The measure also would charge higher fees to employers whose work forces consist of more than 30 percent H-1B workers and prevent firms with more than 75 percent from applying for additional visas altogether.

But some say that doesn’t go far enough to level the playing field, and critics worry about possible loopholes allowing some large employers to avoid the requirements.

“Sure, this would be better than the current law, but it would still undercut the average wages for these sectors,” Ross Eisenbery, vice president of the left-leaning Economic Policy Institute in Washington. “They need to fix the program before they expand it, and fixing it requires forcing employers to pay the full prevailing wages.”

Harsha Setlur, a master’s student in telecommunications engineering at the University of Maryland, said the proposed restrictions “sound like a solid plan” to prevent employers from abusing the program. Originally from India, Setlur will graduate next month and is looking for a job in the U.S.

He may eventually return home to start his own company, he said, but for now, the wages here would allow him to pay back his student loans more quickly. If he finds employment, he will need an H-1B — so he hopes lawmakers will lift the limit.

He isn’t alone on campus, according to Heidi Sauber, director of the career services team at the University of Maryland’s Clark School of Engineering.

“Our students and many of our local employers would like to see, if not no quotas at all, then at least a significant increase in the number of H-1Bs,” she said. “In some of these areas, our country can’t fill the need, and these are students who are eager to work.”

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