Yes you can get vitamin D through your eyes.
We get most of our Vitamin D from the sun through our skin and being out in the sunlight but we also take in some Vitamin D from the sun through our eyes.
Just don't stare at the sun but just being out in the sunlight and having your eyes exposed to the sunlight but not staring directly into the sunlight can help improve your bodies immune system.
We need Vitamin D and Vitamin C and other Vitamins to get a boosted and healthy immune system so that we can prevent cancer, viruses and other health issues from affecting our bodies.
When our bodies immune system is boosted and in good working order then our bodies immune systems can fight off the flu virus, cold virus and other viruses and diseases easier and faster.
So while wearing sunglasses is good it's also good to go out into the sunlight without sunglasses and take in some Vitamin D through our eyes as well as our skin.