When a new school year begins later this month, some Utah teachers will be competing for their students’ attention against a sphere of hot plasma more than 90 million miles away from Earth.

Several Utah districts plan to resume classes on Aug. 21, the same day that a once-in-a-generation solar eclipse will be visible, at least partially, across most of the continental United States.

Granite School District is spending roughly $30,000 to provide protective eyewear to each of its 68,000 students, spokesman Ben Horsley said.

He said Granite campuses will follow an assembly schedule on the first day of school, minimizing disruption to classes from the solar event, which in Salt Lake County will peak at 91 percent coverage of the Sun by the Moon around 11:30 a.m.

"We’ll have glasses available for every student and staff so we can take advantage of this tremendous educational opportunity,” Horsley said Tuesday.

Salt Lake City School District and Murray School District will also kick off the new 2017-2018 school year on Aug. 21, but are leaving eclipse planning up to local school administrators.

Yándary Zavala Chatwin, spokeswoman for the Salt Lake City district, said some schools plan to incorporate viewings into their schedule. The only specific direction from the district, she said, was a reminder to supervise children and take safety precautions if students are allowed outdoors during the eclipse.

Health experts are warning of the risks of severe eye damage from even a few seconds of viewing the Sun directly, even when it is partly obscured during an eclipse. Officials with the John H. Moran Eye Center in Salt Lake City said Wednesday they have already given away 1,000 pairs of protective glasses at optical shops along the Wasatch Front.

Only eyewear that meets certain light-filtering criteria can be used to view an eclipse, as can welder’s glass with a number 14 filter or higher. Pinhole and box projectors, or other do-it-yourself devices, can also be used to indirectly observe an eclipse by casting the Sun’s image onto a viewing surface.

“It‘s a good thing to have this coincide with the first day of school,” Zavala Chatwin said. “We think it will create memorable experience for the students in the district.”

Because of Utah's proximity to the so-called "path of totality" — a strip cutting across the U.S. in which the Moon will fully obscure the Sun for several minutes — many Utahns are expected to travel north to view the eclipse.

Horsley said district parents were asked to weigh in on proposed start dates for the 2017-2018 school year, and a majority preferred Aug. 21 despite the eclipse.

He said some families will probably opt to pull their children out of school that day for eclipse-related activities, but added that the district was not concerned about any disruption from mass absenteeism.

“We communicated this over a year and a half ago when we were advertising the options for the school calendar,” Horsley said. “It will just be marked as an excused absence.”

In Murray School District, spokeswoman D. Wright said some schools will keep students indoors for the event as a safety precaution while others are coordinating monitored viewing activities.

“The superintendent has asked school officials to work with parents who may be keeping their kids out of school on the first day due to this solar event,” Wright said. “But we will not be adjusting our previously-approved school calendar start date.”