Each pair of sunglasses is different and some do not protect your eyes that well. Always make sure any shades you buy offer full UVA and UVB protection. Even if budget sunglasses are your focus, you should remember that they could have a negative impact on your vision.
Omega-3 fatty acids offer great nutrients for your eyes. It's a great idea to eat foods that have omega-3 fatty acids in them. Some foods include tuna, dark, leafy greens, and halibut. Try to eat at least a serving each day.