Sunglasses make great gifts. They’re useful, fun, and fashionable, and unlike clothing, you can’t offend someone by buying the wrong size. However, you do have to pay a little bit of extra attention if you’re trying to find the perfect pair of sunglasses for your man.

Whether it’s Christmas, his birthday, your anniversary, or just because you love him and want to protect his gorgeous eyes, you really can’t go wrong with the gift of sunglasses if you follow these tips for finding the perfect shades for him.

Look at His Face

You love looking at his face so this part shouldn’t be a problem, but we’re not just talking about gazing lovingly at him. Look at the shape of his face. This will give you a good idea for what type of frame to look for.

Related: How to choose sunglasses for your face shape

If his face is oblong, avoid teardrop aviators, as they can make his face look even longer. Instead, go with a pair of chunky rectangles or wrap sunglasses. Wider shapes will balance his face and make it look more in proportion.

If he has a square face with a wide, strong jaw, look for sunglasses with rounded bottoms. The contrast between the soft edges of the sunglasses with the hard lines of his face will be flattering and manly.

If his face is round, go for rectangle or square frames to give it a leaner, more chiseled appearance. If he has a wide forehead and narrow jaw line, choose shades that are wider at the bottom to balance his features more. If he has an oval face, the sky's the limit - he can get away with just about any shape.

Think About His Lifestyle and Fashion Sense

Does your man prefer jeans and a t-shirt, or is he more of a suit-and-tie guy? Is he an athlete? Would he prefer to be out for a run, or would he rather be on a patio sipping a cold beer?

His lifestyle and his clothing choices will also help you choose the right shades for him. A pair of technical sports sunglasses would be perfect for the marathoner in your life, but they won’t go over so well if he spends most of his time in a suit and tie.

Take Measurements

Sunglass sizes are measured in three numbers: width of a lens, width of the bridge, and full width of the frames. So, for example, you might see sunglasses that are sized 55 – 17 – 135. For these, each lens is 55 mm wide; the bridge is 17 mm wide, and the overall width of the glasses is 135 mm.

Related: How to choose the right size sunglasses

If you’re sneaky, you can do this while he’s asleep to avoid giving away the surprise or looking like a weirdo, but you’re going to have to measure his face. First measure across the widest part of his face, then across the width of the bridge of his nose. Subtract the width of the bridge from the width of his face and divide the difference by two to get the measurement for a good lens-width for his face.

With a little bit of attention to the shape of his face, his style, and his measurements, you should be able to pick the perfect shades for him that he’ll love wearing all the time.