How are Prescription Safety Glasses tested?

Today’s world is witnessing the most significant innovation, and it is evident in the market of Prescription Safety Glasses- the way safety eyewear is tested and is made available to the emerging customer base. Safety eyewear is a boon for people who work in a dangerous work environment like factories or labs, where their eyes are exposed to several injuries. Safety eyewear works as a shield against accidents that could lead from severe injuries to permanent vision loss.

According to Prevent Blindness America, every year around 7, 00,000 Americans injure their eyes at work, another 125,000 injure their eyes at home. Over 40,000 American children and adults suffer eye injuries during sports or recreational activities. These numbers are reported, while there are several cases which go unreported.

In the United States, the federal government has established safety guidelines to decrease job eye injury risks. The Occupational Safety and Health Administration (OSHA) has adopted eyewear safety standards set up by ANSI. So, the Prescription Safety Glasses have to conform to Z87. 1–2010 ANSI standard to create efficient safety eyewear.

To ensure the durability and strength of the Prescription safety glasses, they are put under tests using different methods. There are two classifications based on performance: basic impact and high impact.

1. High Mass Impact test– In this test, the safety lens is mounted in a frame and is tested with a heavy projectile. The one-inch diameter steel projectile of 17.6 ounces is dropped on a frame worn by artificial headform, through a tube from the height of 50 inches. If the frame retains the lens and no piece detaches from the inner side of the frame, it means the safety glass lens is highly impact resistant.
2. Durability — Safety lenses undergo flammability resistance test, corrosion-resistance and several other tests to ensure whether the glasses can protect the eyes of a worker in high-temperature work zones or during any fire-related accidents. The corrosion test is conducted to ensure the coating of lenses and frames are rust repellent. Furthermore, the chemical-resistance is tested to see the behaviours of the respective coating when the glass comes in contact with different chemicals.
3. High-Velocity Impact Test– This test is conducted using a quarter-inch steel ball, which is shot at the lens and frame at the velocity of 150 feet per second from 10 inches distance. The test is repeated multiple times, each time with either a new lens or new frame from different angles. To pass the test, the frame has to retain the glass, moreover there must not be any breakage or chipping.

Drop Ball Impact Test

This test is performed with Drop Test Machine from the recommended test height of 50 inches. In this test, a one-inch diameter steel ball is dropped onto the lens from a distance of 50 inches. To clear the test, the lens must not break or chip. Every safety glass goes through a drop test. It is conducted to check the impact-resistance of the lens against heavy objects.

How to know the level of safety provided by Prescription Safety Glasses

1. Plus Mark — It represents if the lens has passed the high-velocity test. If you work at a heavy-duty workplace do look for glasses with ‘+’ sign, it indicates that the lens is impact-resistant.
   This mark also determines durability of the prescription lens of the same or greater thickness, made out of the same material and coating.
2. ‘V’– It is stamped on photochromic prescription lenses
3. ‘S’– It indicates that the lens has a special tint. In shady safety glasses a number may also be marked to state how much light transmission is reduced by the tinted glass.
4. ‘L’ + a number represents the visible light filter rating
5. ‘U’ + a figure shows the Ultraviolet light-scale rating
6. ‘R’ + a number shows the infrared rating filter.

The shading safety glasses are used by workers who are employed in molten metal and soldering, welding and cutting jobs. The tints have different densities- for instance, torch soldering work requires (mild to moderate 1.5 to 3.0) tint density and for electric arc welding up to 10 to 14 density is advisable.

All the safety ratings are permanently stamped onto lenses. They are printed on the upper corner. If the glasses don’t meet the high impact safety standards, then a warning label is affixed, which can be only removed by the wearer.

In Summary

Prevention is better than cure. This is relevant in the case where a person is vulnerable to eye injuries due to the nature of job or engagement in any sport activity. It is always better to take precautions rather than to suffer. So, why not invest in a pair of safety eyewear?

CA Glasses is your one-stop solution for all your eye protection concerns. You can find the Best Prescription Safety Glasses here. So, head straight to select your pair now!