Why can’t you look at the eclipse? Here’s how to DIY safe viewing glasses

Eclipse takes place on 8 April

On Monday 8 April, a total solar eclipse of the sun will take place across the United States, Mexico, and Canada.

During this eclipse, the moon will pass directly between the sun and Earth, which will block out the sun’s rays and make the sky dark in the middle of the day. However, if you want to view this astronomical event, proper precautions need to be taken.

An eclipse goes through phases in which a person can view the moon slowly moving in front of the sun. This is called a partial phase. During these phases, Nasa recommends wearing protective eyewear, which must specifically meet the ISO 12312-2 international standard.

If glasses are not your thing, you can also look at the eclipse using a telescope, camera lens, or binoculars, but they must have the proper filter over the top to avoid causing any eye damage.

Viewing any part of the bright sun through a camera lens, binoculars, or a telescope without a special-purpose solar filter secured over the front of the optics can instantly cause severe eye injury, according to Nasa.

Looking at an eclipse without eye protection can cause “eclipse blindness” also known as solar retinopathy. This means the light from the sun can burn the back layer of the eye, known as your retina, which converts light into electrical signals. Those signals are sent by the optic nerve to the brain to create the image a person sees.

Mild symptoms of solar retinopathy can include watery eyes, eye soreness, headaches and light sensitivity but more serious symptoms include blurry vision, blind spots, dim vision, distorted vision, eye pain or blindness.

It is recommended that those who believe they may have a retinal burn contact an ophthalmologist or optometrist immediately.

The glasses and filters that are appropriate for viewing an eclipse are essentially a thousand times darker and more powerful than sunglasses, and the fashion accessory is not recommended as a replacement for the approved standard ones.

In addition to many places giving out approved glasses to view the eclipse for free, Nasa has also provided instructions for how to make your own eclipse projector.

This projector, which is called a pinhole projector, works when the sun is facing your back, and then allows users to look at a projected image of the sun on a nearby surface.

To make one of these projectors, all you need is a small cardboard box the size of a cereal or shoe box, a white sheet of paper, tape, scissors, aluminum foil, and a push pin.

First, trace one end of the box onto the piece of paper and then cut it out and place it inside the box on the same end you traced. On the opposite end of the box, cut two square holes. Cover one of the squares with aluminum foil and tape it down. Use the push pin to pop one hole in the centre of the foil.

To accurately use your pinhole projector, turn your back to the sun and look through the hole next to the one covered with foil. You should be able to see the image of the eclipse (a crescent sun) projected onto the white piece of paper as the light streams through the hole in the foil.

You can safely view the eclipse without any protective eyewear when the moon has completely covered the sun during a period of time known as totality. This period typically only lasts a few minutes and any filters or coverings should be placed back on once any sort of light begins peaking through again.

Totality of this eclipse is reported to last up to four minutes and 27 seconds and will start and end at varying times, depending on your location. For example, in Dallas, Texas, totality starts at 1.40pm CDT and ends at 1.44pm CDT and in Caribou, Maine, it starts at 3.32pm ET and ends at 3.34pm ET.

But, if you aren’t planning on making your own pinhole projector, many retailers are offering proper eyewear to use.

For example, Warby Parker is giving away free, ISO-certified solar eclipse glasses at all stores from 1 April until the eclipse on 8 April. They are limiting the glasses to only two pairs per family.

You can also possibly pick up a pair of glasses from your local library.

With help from Gordon and Betty Moore Foundation and the Space Science Institute, The STAR Library Network has been able to ship five million solar eclipse glasses to 10,000 public libraries across the country with assistance from Gordon and Betty Moore Foundation, the Space Science Institute and STAR Net’s Solar Eclipse Activities for Libraries program. They are offering one pair per patron at specific libraries.

New York State is also offering members of the public an opportunity to get their hands on two free ISO-certified pairs of “I LOVE NY” solar eclipse glasses, according to the I LOVE NY webpage.

The free pairs of specs are given out daily at New York State Welcome Centers, select Thruway Rest Stops, and other locations listed on the site while supplies last.

“Please note that there is no guarantee that glasses will be available as demand has been very high,” the website reads.

Jeni’s, a Columbus, Ohio-based ice cream brand, will also be giving out four pairs of eclipse glasses with purchase of the “Punk Stargonaut collection,” which are four “out-of-this-world flavours” launched to celebrate the eclipse. People can start purchasing the ice cream online starting on 28 March and in Jeni’s ice cream parlours starting on 5 April.

Sonic has also come up with a signature menu item to celebrate the upcoming eclipse. The fast food chain has announced its Blackout Slush Float and will be giving away one pair of eclipse glasses with every purchase of the drink while supplies last. The drink promotion will last through 5 May.

Starting on 27 March, people can also purchase an eclipse-themed drink at Smoothie King until 8 April. The Eclipse Berry Blitz is made with “bananas, wild blueberries, apples, blueberry juice blend, white grape lemon juice blend, protein blend and blue spirulina, a blue-green algae powder”.

Customers who buy an Eclipse Berry Blitz at a participating Smoothie King location within the path of totality will also get a free pair of eclipse glasses while supplies last.

But, if you’d rather have the eclipse glasses delivered straight to your door, there are many options available in packs on Amazon. The key is just to make sure that anything you use for the eclipse is ISO-approved.