For those of us that wear reading glasses. They are a godsend; they magnify the letters so you no longer have to stretch your arms to their fullest extent to read. Nor squint to try and make the words clear. So why should we consider anything else?
Well, I believe that you should seriously consider ordering progressive or bifocal lenses instead of reading glasses for your safety glasses. And this is why: Safety glasses are a form of eye protection if you are having to take the glasses off to walk around then you are putting your vision at risk.
The main reason for my belief centers around the lack of flexibility of a single vision lens. Bifocal and progressive lenses can see in both the distance and up close which means that you can walk around safely.
Reading glasses are only clear for reading and generally only have a 20cm depth of focus. This means that anything past the distance that they are set for will be blurry and that you cannot walk around in reading glasses safely.
Most environments where you must wear eye protection require you to leave the safety glasses on your face. This means unless you have another pair to put on to walk around you will be walking around unprotected.
Should this person be your employee then unfortunately you may be liable for not providing the correct eye protection.
So, what type of lenses do you order? It is difficult as an Employer knowing what the right pair of safety glasses is to order for your staff. Particularly if they need prescription safety glasses. Looking at an optical prescription you can tell if you need reading glasses (additional help when looking up closely) if an Add is mentioned on the prescription.
If you must work up close all day and don’t need to walk around at all. Then you might be able to get away with just reading glasses. Or even a pair of magnifying bifocal safety glasses might be sufficient. (As many farmers have found for driving their tractors while seeding or harvesting).
What are progressive lenses? Progressive, graduated or varifocal lenses are all the same type of lens. Which in its traditional form has 3 different prescriptions ground into the back surface of the lens. They have a corridor of clear vision that is shaped like a tree. The distance has the widest field of view (the branches of the tree), this prescription changes to the intermediate prescription as your eyes move down the lens (this is the trunk of the tree portion of the corridor of clear vision). The intermediate prescription is generally around an arm’s length away (so the bit of your lens is clear for the computer).
As your eyes progress further down the lens to the reading portion (the roots section of the tree). It is generally located at the bottom of the lens.
Bifocal lenses are lenses that have two prescriptions located in the lens. The distance between the top of the lens and the reading portion of the lens is in a D-shaped segment (on its side) at the bottom of the lens. As your eyes move through the line at the top of the reading segment of the lens. Initially, when you get bifocal lenses the top of the lens can cause an image jump (but you quickly get used to the lenses at the image jump disappears).