Admit it…that subject line was weird enough to grab your interest. 🙂
So here’s the deal. I need my glasses for distance and for reading, and rather than do bifocals, I do progressives. Easy peasy lemon squeezy. I have had progressives since I was 19, and for 33 years, I’ve had no optical issues. I’m not a candidate for laser surgery to fix my eyes and I probably wouldn’t even if I could. I have no real problems with my glasses, and even when I can take them off, I just leave them on. They don’t bother me, and I feel I look weird with them off.
But I recently bought new binoculars for astronomy, and I was struggling to get them to work reliably to focus. I thought it was a bit weird until I did some reading about it, and something jumped out. Using my binoculars, my prescription doesn’t normally affect anything — and I tend to take my glasses off anyway given that it is monocular experience and I like having my eye close to the eyepiece to block stray light from the sides. I can wear glasses or not, but I prefer to observe without. On the ‘scope, I can adjust either way but I never really thought about why I prefer without — but it’s the issue of exit pupil.
With binoculars, it has the option to correct for distance AND astigmatism, BUT I should be able to still wear my glasses. I specifically bought binos that let me do that. But when I used them, I really struggled. Someone online had written some articles about optometry and astronomy and noted that if you had bifocals or progressives, then using binos becomes REALLY HARD. Think of it this way — your glasses slowly progress from distance Rx at the top to a close reading Rx at the bottom, so how do you ensure that you are lined up for the right “distance” point on your glasses when you put your binos to them? Lots of people find it really frustrating, without necessarily understanding why. The pure physics of lining up a changing Rx across the surface of your glasses with your eye and the binos.
What’s the solution? Put your binos to the top of your glasses helps, but it still changes over the range of the glass. Take them off. Or you can get a pair of prescription glasses that are ONLY for distance and that correct your astigmatism.
Well, okay. But glasses are kind of expensive, and there are a lot of views in the astro community about the material for the lens, design for the glasses, blah blah blah. We live and die by optics, so not surprisingly, lots of people have views. I’ll write it up in more detail at some point but basically I wasn’t ready to pull the trigger on anything expensive until I knew for sure this was going to work. Very few astronomers have ever bought glasses just for astronomy, it’s not really a “thing”. Or as my optometrist put it, I do bring her interesting questions.
One of the guys on Cloudy Nights had ordered a pair online, choosing the cheapest pair he could find through Zenni which sells discount glasses. Plastic, not glass, super lightweight i.e. flimsy frame. Almost like printing a prototype for something more serious later if it works. How much do they cost? About $7 for the glasses and frames. Seriously. Okay, it’s US, and I had to pay extra for my specific prescription curve (about $3), plus shipping, no coatings so no extra charge there, and I ordered an extra pair of nose cones.
They arrived today, and I wasn’t really sure what to expect. I knew they would be small (I deliberately went for the smallest / cheapest frame that was wide enough for my head) and knowing that I might use them 10-20 times a year, I didn’t want too many bells and whistles on the prototype. Here they are, by themselves, on my face, and sitting next to my normal glasses.
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But they are for seeing, not being seen, so I dug out the binoculars, went into the backyard, rested my hands on the table to steady them and focused on Jupiter. At first, I had the same results as previously. A lot of initial trouble to bring Jupiter into actual focus. With the brightness, I definitely get chromatic aberration from the binos, that was to be expected, BUT after a few minutes and my eyes adjusting to being outside and with the distance lenses only, I had success. I was able to bring Jupiter into a relatively round ball (still way too bright for details) AND I could see the Galilean moons. I would need to get the binos on a tripod to do better than that, but that’s about the binos, not the glasses.
In short, the glasses worked as designed. I look forward to trying them with all my different eyepieces, and I’m curious if I will now leave them “on” to do my astronomy or I’ll revert to taking them off. We’ll see. There’s a challenge with one aspect of it which is that I’m frequently having to read while using the scope, so bifocals might actually be preferable (i.e. I could leave them on to do both viewing AND reading), but not sure I will keep using them for other things besides bino work. I MIGHT try wearing them for driving, they are designed for that, but not really what I want. I like my main glasses, but happy to have “resolved” (no pun intended) my viewing with my binoculars.
In the meantime, today I choose to play with my glasses for astronomy.
What choices are you making today?