As of July 26, 2017, I have been using reading glasses. What finally prompted me to go ahead and purchase a pair was in the months prior to this, was when I had trouble reading the stamping on my PR flange based flashlight bulbs. My eyes couldn’t focus in on the information written on the bulbs unless I held them a very few inches from my eyes and I still had to strain and squint.
When one works on flashlights as much as I do, especially with a diverse amount of battery sizes and arrangements, knowing which bulb to place in which flashlight is critical. Placing a bulb designed for a lower voltage than the flashlights battery voltage and the bulb burns out very prematurely or even instantly. Technically though, all flashlight bulbs are indeed over driven. On the other hand, however, placing a bulb designed for a higher voltage than provided and it will be extremely dim and also run down the batteries prematurely. It’s simply a balancing of equations if you will. The little bit I remember from high school Algebra is that whatever is done on one side of the “equals” sign must also be done on the other. This principle also applies on doing any sort of electrical work, where the load and power source must be balanced. Luckily, many years ago, people of their respective fields in the science of flashlight bulbs came out with a numbering system.
Here are a few examples:
A Standard PR2 bulb is designed for use in a flashlight that runs on 2 D Cell batteries in series or 3 Volts. Its electrical values are rated at 2.38 Volts and 0.5 Amps.
A Standard PR3 bulb is designed for use in a flashlight that runs on 3 D Cell batteries in series or 4.5 Volts. Its electrical values are rated at 3.57 Volts 0.3 Amps.
A Standard PR13 bulb is designed for use in a flashlight or lantern that runs on 4 D Cell batteries in series or a single 908 lantern battery, either configuration results in 6 Volts. Its electrical values are rated at 4.75 Volts 0.5 Amps.
A Standard PR12 bulb is designed for use in a flashlight that runs on 5 D Cell batteries in series or 7.5 Volts. Its electrical values are rated at 5.95 Volts 0.5 Amps.
Have I not indeed stated that all flashlight bulbs are technically over-driven? Above is proof.
However, when a bulb is over-driven beyond the point of it’s design, like placing a PR2 bulb in a 5D Cell flashlight, it will burn out in a very bright white flash that lasts mere milliseconds. And if a bulb is under driven, like placing a PR12 bulb in a 2 D Cell flashlight, it will come on, but be miserably dim and eat the batteries like the starving cat locked in the fish market overnight.
If there are any fellow flashaholics out there reading this, I am almost sure you’re thinking of placing a PR3 bulb into a 4 D Cell or single 908 Cell flashlight. Yes it is possible and yes the bulb will burn very bright, but the bulb life will be cut down significantly. Flashlight bulbs are getting harder and harder to find as the years go by, so I’d advise not to waste them. I’ll go even further and say make them last as much as humanly possible.
Anyway, this piece is about why I use reading glasses, and not necessarily a lecture about flashlight bulbs. My inability to read the stamping on my flashlight bulbs with just my natural sight was the catalyst for me deciding to purchase reading glasses. In other words I need to know that the bulb I am installing in my 2 D Cell flashlight is a PR2 or the bulb I am installing in my 6 Volt Lantern is a PR13. Therefore I need to be able to see what is stamped on the base of the bulbs.
I will say one more thing about flashlight bulbs then move on:
I am a firm believer in using (or at least stockpiling) incandescent flashlights and their respective bulbs. Yes, they are much more flimsy and much less efficient than their LED counterparts, but, they are user serviceable (though a little bit of electrical and mechanical knowledge is required) AND more importantly, they will survive an EMP blast while probably most if not all LED flashlights will perish. Also in the event of such an occurrence, the electrical grid will be down as well. Any device that employs an integrated circuit chip or transistor will be ruined. That means no modern car will start and virtually all telecommunications will be gone. How will people safely light their homes and hunting, farming and fishing areas at night? Combustion type lighting will be highly frowned upon because no fire department will be able to coordinate and respond in the event of a structure fire or wild fire.
Okay, I am getting ahead of myself, but this is the exact reason why I believe so much in incandescent flashlights.
Back to the glasses.
With my new specs, I can easily read the stamping on my flashlight bulbs, but not only that, I can read the finest of print with great ease.
It was indeed flashlight bulbs that made me realize I needed to use reading glasses. However, since the age of nineteen, I can remember trying to read an atlas or school book with my natural sight and seeing the words on the pages go in and out of focus. I never thought much about it, except that reading books was a difficult task for this and other reasons. The best way I can describe the issue is that it was like watching one of those portable [analog] televisions with a slide rule tuner, where one constantly had to ever so slightly turn the knob to get the picture just right. Another analogy would be like watching a thirty year old VHS tape and constantly having to adjust the tracking. Those of you reading this who are younger than me won’t understand these obsolete technologies, but my fellow [older] Millennials as well as GenXers and Baby Boomers know exactly what I am talking about. If there are any Silent or GI Generation members reading this, I am honored by this and I hope my work is at least amusing to you. I also hope you’re not too offended by some of the controversial things I have written over the years.
So, when I read a book, small print, or do any close up work that requires keen vision, I use my glasses. Sometimes I use them to write as well. I’m using them as I write this piece, in fact. The difference is when I use these glasses, it is like watching a digital television with a 1080p screen connected to a high quality amplifier and outdoor antenna. Another analogy would be like watching a Blu Ray DVD on its respective player, connected to that same television through the HDMI terminal. That’s an analogy that the younger Millennials and Post Millennials should be able to relate to.
Currently I use the lowest strength available, 1.00. Of course I’m only thirty at the time of writing this and maybe I’ll require stronger glasses as I age and maybe not. I’m not sure if I like how they make me appear, but most people who have seen them on my face have commented favorably.
If you, are having minor vision issues consider a using a pair of reading glasses, but more importantly follow the advice of your optometrist.
Thank you for taking the time to read this…