FILE - In this photo taken Friday, Aug. 18, 2017, Poureal Long, a fourth grader at Clardy Elementary School in Kansas City, Mo., practices the proper use of eclipse glasses in anticipation of Monday's solar eclipse. Credit: Charlie Riedel / AP

The special glasses that allow safe viewing of the sun are an essential tool for enjoying the solar eclipse that’ll be passing through Maine on Monday afternoon.

Except for the brief period when the moon is totally blocking the sun — a phenomenon that will only be visible in a handful of communities across northern and western Maine — it’s never safe to look directly at an eclipse without that special eye protection.

So it’s no wonder that those glasses have become one of Maine’s hottest commodities in the days leading up to the once-in-a-generation celestial event. But just how precious are they?

On Saturday, the BDN did a small survey of places across Maine to assess whether they’re still available. For those making last-minute eclipse plans, the good news is that they are.

The bad news is that they’re going fast. About half of the places surveyed had run out, and many of those that still have them appear to be in the remote areas that are expecting the most visitors for the eclipse. In some cases, the places that have them are also going to be closed on Sundays.

Here are some places that still had the glasses as of early Saturday afternoon — though supplies were getting low at some of them, and calling ahead would be wise:

Auburn: Auburn Public Library (getting low)

Bangor: Bangor Public Library (getting low)

Bingham: Jimmy’s Shop & Save

Bethel: Maine Mineral & Gem Museum

Dover-Foxcroft: Shaw’s supermarket

Greenville: Indian Hill Trading Post, Shaw Public Library

Houlton: Multiple locations, including Eclipse Headquarters, Maine State Visitor Information Center, and local businesses

Millinocket: Millinocket Memorial Library

Portland: Portland Public Library (getting low)

Rangeley: Multiple locations, including Rangeley IGA, Rangeley Public Library and Rangeley Lakes Chamber of Commerce

Rockland: Shaw’s supermarket (getting low)