The sixth-grade English class at the Westtown School in West Chester was buzzing with kids eager to talk about all the things they'd just seen in Kenya's Dadaab refugee camp – one of the world's largest, teeming with people fleeing violent conflict in neighboring Somalia.

"In the camp, it was so crowded," said Stella Costabile, talking about the family of seven she'd seen sleeping on the floor of the cramped living quarters. A classmate voiced surprise at the large buses and trucks rolling down streets, just like in a large city, while others talked about how most of the people they saw were women and children.

The sixth graders had plunged themselves into the refugees' world without ever leaving the comforts of their Chester County classroom: They explored the Dadaab camp through the computer-generated technology of virtual reality – donning high-tech goggles and headphones to explore 360-degree footage of the camp shot by the New York Times.

The students at the K-12 Quaker school this fall joined a small but rapidly growing number of classrooms in the Philadelphia region turning to virtual reality (VR), or its less immersive cousin, augmented reality (AR), as a teaching tool that energizes kids by taking their class on artificial field trips to ancient cities halfway around the world, and on expeditions to Mars, scuba dives on Australia's Great Barrier Reef, or on fantastic voyages inside the human body.

The use of virtual reality in schools has risen exponentially in the last couple of years, thanks to advances in technology that have widened the array of experiences and made VR more accessible and, perhaps more important for cash-strapped districts, more affordable. The introduction of Google Cardboard – with goggles as inexpensive as $5 that attach to a smartphone – have spread the use of VR, although more ambitious districts are spending tens of thousands of dollars on labs with state-of-the-art VR goggles and computer technology.

At the Westtown School, where a parent council recently donated 20 VR Shinecon goggles (which cost $580 total), technology integration teacher Alicia Zeoli said this was the second year of teaching a unit on refugees but the first time using VR – and the difference was powerful.

"They felt more empathy after they watched the video," Zeoli said. "It felt like they were on the boat. … That's one of our biggest goals in the school, to build empathy. How do you do that when they're 11 and live over here?…We're definitely not taking them on a field trip to Syria."

"VR is best for things that can't be normally done in a classroom," said Joseph South, chief learning officer for the International Society of Technology in Education, who echoed other advocates that VR should be an occasional classroom tool that can make far-off places or complex environments more accessible to kids. Virtual reality, he said, is "exposing them to learning environments … that [otherwise] wouldn't be possible for them to experience. It can be quite powerful."

The educational value of those experiences has prompted some schools to invest more heavily in VR labs like the kind offered by vendor zSpace, which has reported selling New Jersey districts roughly 15 units – costing as much as $60,000 for the equipment, software, and training – as part of a nationwide push into about 500 schools.

One of the first Pennsylvania schools to purchase the zSpace equipment is the Valley Day School in Morrisville, which teaches children with emotional, social, and learning differences. It spent $53,000 for 13 computer stations.

Eric Dixon, a computer technology teacher at the Bucks County school, said VR is proving an invaluable tool for kids with autism or attention-deficit issues who might struggle with more traditional modes of instruction.

"We can see the light go on and the sign of epiphany," Dixon said of projects such as students virtually dissecting earthworms, adding: "If their normal attention span is 12 minutes, we can expand that to 20, 25, 30 minutes."

On a recent day, Dixon worked with a high school physics class using a zSpace program to teach about the principle of force transfer and collisions. The students used pens attached to computers to move cars across their screens, rotate and take their vehicles apart to examine parts and examine crashes to learn how cars absorb impacts. The special eyeglasses made the images pop off the screen into 3D.

"Mr. Dixon, isn't the crumple zone of a Smart Car the whole car?" asked 10th grader Damien Noble, 16, who was particularly skilled at manipulating the virtual vehicles.

Augmented reality means adding a layer of digital input like graphics – the first-down line on a football telecast, for example – or sound to the real world. Virtual reality uses goggles and headphones to create a 360-degree experience of total immersion. Schools entering the world of VR are sorting through a wide array of technologies, from Google Expeditions and the popular Pokemon Go that use AR to plant virtual objects in the real world, to more advanced VR glasses that can cost up to $1,000 apiece.

Christopher Dede, the Wirth professor in learning technologies at Harvard's Graduate School of Education, said schools are figuring out which VR or AR technology best fits their needs but also how to integrate this newfangled tool into their curricula. He questioned whether the added value of a virtual experience is enough to justify the high cost.

Dede cited the example of the immersive visit to a refugee camp "so you feel present in the virtual environment in a way that you don't feel present in an educational video. How much is that worth? It's worth something. Is it worth $10,000? I'd say no."

"It's a not a fad," countered Aaron Heintz, technology integration coach for the Philadelphia Archdiocese's Office of Catholic Education, who said seven parochial schools in the region are investing in Google Cardboard or Expedition kits — the major difference is the type of case holding the phone — and he expects more to soon follow. "This is something students use in their world."

At St. Patrick's School in Malvern, students this year have used Google Expeditions to visit the ruins at Machu Picchu, explore Native American culture, and dive into the diverse ecosystems of the Galapagos Islands. In one recent class, 25 sixth-graders oohed and ahhed as their teacher Christopher Fender guided them past sea lions and around scuba divers and sharks.

The kids agreed: VR makes what was the high-tech learning tool of their parents' generation –  television – seem old-fashioned. (When their parents went to school, video involved television, not computers and 3D.) "You can walk around with these and learn and see different things," said 11-year-old Mimi Pasquale. "With a TV, you're sitting there watching it."