Yes, generally speaking, police sunglasses are polarized to protect your eyes. So you should not need to worry about it. Also, you should know that police sunglasses are a brand which is famous for its unique style. Striking qualities, passions, occupations and an extremely original sense of styles are the basic principles. They are made in Italy and have market all around the world. In my opinion, you can buy them on online shop, which can be as good as the real stores, but they are cheaper. Also, they will provide you many styles so that you can choose. The prices of police sunglasses vary from 100 dollars to 170 dollars. So you can just choose one pair you like.
I am not sure that if all police sunglasses are made with polarized lenses, you need check it yourself or ask the seller. In fact, compared other brands design sunglasses such as bvlgari sunglasses, Police sunglasses are really affordable. You can get a pair police sunglasses at the low at less than one hundreds dollars. Of course, the price of Police sunglasses are different. There are some of them priced over one hundred or almost about two hundreds. Anyway, it is more affordable than other brands, you can have a try.
The police sunglasses will cost $120 at average. They are not all polarized with the design. If you use it to go fishing and drive, you could pick the police sunglasses with polarized role. In addition, you could go to the http://www.sunglasses-shop.co.uk/police.aspx to have a search. There are many types there.