should I take both pairs of glasses?

I wear glasses- have prescription sunglasses ( that my rear view mirror clips to) SHould I carry my regular glasses on a long ride (BDB)? On a retainer or in their case in my Jersey pocket?
Opinions please!

I usually carry both - prescription glasses & sunglasses. When it starts getting dark or around twilight, having my glasses makes it a lot easier to see.

I usually have a hydration pack on, so they just go in the side pocket of that. I have a pair of safety prescription glasses that work made me at some point, so I just keep those permanently in my backpack for riding.

I wear my contacts and my beloved Rudy Project (Rudy Girls) sunglasses. I have clear lens to go in them that snap in and out easily that I carry in my saddle bag all the time. In case of changing light conditions etc. Lens come in a variety of colors, break-age strengths... and rx correction.:)

I can't ride anyway now since my crash, but I *wish* I had the rx sunglasses inserts for my Rudy's as a back-up. Blood in the eye, so been wearing my one pair of regular non-sport specific glasses. And I get migraines trying to drive in the sunlight. So, for sunglasses now, I have some $15 clip on deals from Walmart optical. Think my regular specs have gotten a couple lens dings from them. Ick.

I think Oakley brand might offer this option for rx inserts for sport sunglasses too.

Just an idea as carrying the snap in lens only is much smaller and lighter to deal with. And versus the risk of losing the other set of glasses in whole if they fell outta the jersey pocket etc.

I had a pair of "transitions" (they used to be called "photogray") sport glasses made, and they are perfect for any situation. No more carrying extra glasses!

+1 to Miranda's suggestion.

I wear contacts 97% of the time so I haven't yet dealt with the expense & complications of prescription sports sunglasses, but I have commuted in the morning and at night. Even at night, I like to have eye covering. Dust, bugs, rain, pebbles and wind can all cause vision problems even when it is dark. So I have a pair of sunglasses with interchangeable lenses that have a clear lens option that I take with me if I'm going to be out in light and dark conditions. It's very helpful and easier than carrying two pairs of glasses.

Granted, RX sport sunglasses are $$$$$. Since mine are not RX and they are humble Tifosis, they were not $$$$$, so it was an easier decision.

I just get prescription sunglasses at costco - they end up something like $100 or so. Probably less coverage than sport sunglasses, and I've actually got a set of those with interchangeable lenses that are in the bottom of my camelbak if I need them.

I've never gotten contacts since I work in a lab, and I'm really bad at personal maintenance type stuff beyond showering and brushing my teeth. And because I only wear my glasses if I need to see far away - driving, biking, kayaking, and watching powerpoint presentations. Otherwise, I just find them annoying.

The spare pair of normal glasses in my biking pack works reasonably well, and I've got another old pair of glasses that I keep in my kayak.

I carry my "dress" glasses with me if we will be biking to lunch or going in somewhere. I recently ordered a pair of sport frames with transition lenses to use for cloudy days or getting close to twilight. I tried a pair of Oakleys a few years back , but the wrap around was too extreme for my astigmatism. Unfortunately I need a pair with flat lenses, but these ones I ordered have more protection than my dress glasses. I hope they work for me, they haven't come in yet for me to try them.

I wear contacts, but I have reading glasses that I wear a lot, too. I carry them in my bag when I am riding alone, because if I had to change a flat, I would need them.
I have Tifosis with the interchangeable lenses, but I tried wearing the clear lenses the other morning when I rode at 5:30 AM and they just seem to distort my vision. I have ended up taking them off every time i have ridden in the dark.

My prescription glasses came with magnetic clip-in shades that go over the prescription lenses, very convenient. I just keep the flat case in my rack or seat bag.