Let me start by saying, I love my sunglasses. I bring them almost everywhere with me, but I choose not to wear them on my morning commute. My morning commute has me heading North nearly the entire time, so certainly if I was facing right into the sun, I might consider wearing sunglasses if the brightness was too much.
When the sun is lower on the horizon, there is an increase in the ultraviolet radiation that can enter our eyes, so I do not promote sun gazing, but behind a window or a windshield, we are protected from this UV radiation.
It turns out that exposure to daylight, particularly early in the morning, can help to normalize your circadian rhythms. It can help with mood, sleep, alertness and as I learn more about syntonics, aka optometric light therapy, the more I see the positive impact of getting light energy from the greatest energy source in our solar system, the sun.
Anyone who experiences SAD, seasonal affective disorder, or has used a SAD light knows the impact that a change in season, especially here in Northern BC, can have on your mood and even mental health. I use a SAD light most mornings during the winter months, but nothing beats the mood elevation and energy you get from a nice sunny day.
Sunglasses are awesome, and for your eye health I absolutely recommend that you wear them even on overcast days, but the next time you wake up to a nice sunny morning, I invite you to delay wearing your sunglasses until after 10 am.