It depends on the sort of laser you're talking about, but the general answer is ABSOLUTELY NOT. SUNGLASSES DO NOT PROTECT AGAINST LASER LIGHT! Sunglasses protect well against UV light. They allow a lot of visible light to pass, which is why you can see through them. Above about 800nm most sunglasses have a transmittance close to 100%, so they do basically nothing against lasers that emit in the infra-red part of the spectrum. If you value your sight, buy protective eyeware designed for the laser you're dealing with.
Yes, the real sunglasses with coating part will protect your eyes from lasers because the sunglasses own the ability to protect your eyes from the uv rays and other bad lights. It is the role of the special coating part. When you go out in summer, you could wear the sunglasses to protect your eyes.
Well, as a matter of fact, sunglasses are supposed to protect our eyes from some damaging lights, such as sunshine, or reflected lights. However, you should understand that those sunglasses could not cope with lasers, which are extremely strong and harmful to our eyes. Because the lenses of the sunglasses could not reflect or resist the lasers. So, you had better stay away from lasers.
Well, of course, there are many types of sunglasses which can protect your eyes from lasers. Generally speaking, sunglasses are designed for uv protection and sunlight. So you can go outside and have sports activities with sunglasses. But on the other hand, there are also some sunglasses which can help you to protect your eyes from lasers. For example, the army laser goggles. Anyway, you can just link to http://www.ebay.com/sch/i.html?_ipg=&_from=&_armrs=1&rt=nc&_nkw=Army+Laser+Goggles. And in this place, you will find many types, and they can just cost about 150 dollars.