With spring and sunshine on the way, the need for new sunglasses is strong. When trends are constantly changing, it is important to know when to splurge and when to save.

The basic rule for any investment piece is it’s ability to move from season to season without becoming tacky or out of style. The best sunglass styles to invest in are more classic versions like Wayfarer, aviator or cat-eye. Find these shapes in neutral, flattering colors. It is also important that the frame works well with one’s face shape.

The oval face shape is the most versatile, working with almost any frame. For those with a more defined shape, choosing a frame shape opposite of face shape is a great way to add contrast. Square face shapes look best in curvier frames like round or oval-shaped, while round face shapes look best in rectangular styles. Heart face shapes should aim for frames that are wider at the bottom, like aviators or oversized frames to balance out a wider forehead and narrower chin.

If the pair of sunglasses is likely to lose momentum as the seasons change, or if you’re one to leave your glasses on central campus, it is best to save. Stores like Forever21 are likely to have trendier pieces at an inexpensive price point. One can purchase a few pairs to change up their look throughout the season without breaking the bank.

Inexpensive sunglass trends are bright colored frames, transparent plastic frames or John Lennon inspired circle frames.

Follow your instincts on whether to splurge or save. If a pair of sunglasses feels perfect and you know you will wear them in seasons to come, then go for it. But if you are likely to lose them or get bored of them, it may be best to save and go with an inexpensive pair.