I recently discovered a whole new category of biking sunglasses. Safety glasses. They are wraparound with minimal frames that are adjustable in several ways, come in various tints, and are dirt cheap--most less than $7! There are varieties that look just like sunglasses. Also, they come in anti-fog versions and it really does work. I have clear for night, yellow for dusk, and for sun I prefer the more lightly-tinted ones for the reason you are asking: they're good in both sun and shade. And that's my recommendation: whatever you get, don't get anything darker that you absolutely need and you will find it good in most lighting situations.
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In the US, a good brand and my favorite style is the Pyramex Rendevous ($2.79!) Lose them, break them, get tired of them . . . at that price it really doesn't matter.
https://www.amazon.com/stores/page/B...ridPageIndex=2