Parametrek runs an awesome site for flashlight selections. http://flashlights.parametrek.com/index.html. They’re super knowledgeable and I have found it to be an invaluable resource for identifying options based on your selected parameters. I agree high CRI, rechargeable headlamp is a great option. Rechargeable means you don’t need to worry about specialty batteries and chargers which accompany many of the higher quality enthusiast flashlights available. It might still have a different battery than you’re used to but you can charge it in situ.

FWIW if you do want to just rubber band something to your glasses wing, there is a Lumintop IYP365 (In Your Pocket 365 days a year) it has a high CRI Nichia LED option which is great quality and runs on standard batteries - Eneloop rechargeables are a great option. I read feedback from people who use it as an inspection light in the aircraft industry and their feedback on the colour quality of the light sold me. It’s like a medical quality pocket light where the way colours appear while under illumination is obviously critical - just doesn’t have the M.D. price tag.