A new pair of glasses can completely transform your look. And you get multiple chances to show off the new you, too: glasses prescription expires every one to two years, so if you want to change things up, you can totally do that. But if you want the maximum impact possible, you should make sure you get a pair that work with your face shape, skin tone and even your personality. 

Not sure where to start? With thousands of glasses options available online and in-store, you'll want to consider multiple factors to ensure your new pair complements you. Luckily for you, our guide tackles how to pick the perfect pair. 

How to determine your face shape

Your face shape should be a vital factor in determining the style of frames you buy. After all, selecting the right pair enhances your facial features. Now, how do you determine the shape of your face? Your cheekbones, forehead width and jawline length compose your facial shape. Here are the main characteristics of different face shapes, celebrities who share them and which frames are big no-nos to buy. 

Round face

Round faces tend to be more symmetrical in nature -- evidenced by your face having relatively equal length and width. Your jawline or chin might also possess a round appearance. There won't be any hard angles, and the cheekbones won't be the center of attention. 

• Celebrities with round faces: Selena Gómez, Drew Barrymore, Leonardo DiCaprio and Kate Bosworth
  
• Frame shapes to avoid: Small or round frames clash with rounded facial features. Instead of highlighting its strengths, it accents the shape of your face, making it appear rounder. 
  

Oval face 

Oval faces are longer than they are wide. You'll notice other distinguishing features like a rounded chin and jawline and a wider forehead. With a longer face and rounded features, it naturally forms an oval. 

• Celebrities with oval faces: Jessica Alba, Gigi Hadid, Adam Levine and Mila Kunis
  
• Frame shapes to avoid: Larger eyeglass frames will disrupt the symmetry of your face. 
  

Heart-shaped face 

How does a face make a heart shape? Start with a prominent, wider forehead. Then, as your eyes trace down, you'll notice plusher cheekbones, with the angles becoming sharper, finishing with a pointed chin -- similar to the bottom of a heart. 

• Celebrities with heart-shaped faces: Reese Witherspoon, Nick Jonas, Scarlett Johansson and Naomi Campbell
  
• Frame shapes to avoid: You'll need to take attention away from your forehead to make your face appear more symmetrical. With this in mind, refrain from any frames with embellished tops. 
  

Square face 

The jawline is the focal point of a square face, as it will have sharper angles than other facial elements. Moving up from the jawline, you'll notice it shares the same width as your cheekbones and forehead, creating a symmetric, square appearance. 

• Celebrities with square faces: Angelina Jolie, Cristiano Ronaldo, Sandra Bullock and Demi Moore
  
• Frame shapes to avoid: Don't go for glass frames (boxy or angular) that share similar angles to your face. The result would make your face appear larger than it seems. 
  

Diamond face 

Your cheekbones will be the most prominent feature of a diamond-shaped face. Your forehead and jawline are smaller, allowing the cheeks to take center stage. Because they are somewhat similar in shape, the one differentiating factor between heart-shaped and diamond faces is the width of your forehead. Heart-shaped faces tend to have wider foreheads than diamond-shaped ones possess.

• Celebrities with diamond faces: Viola Davis, Tyra Banks and Liz Hurley
  
• Frame shapes to avoid: Narrow frames won't be your facial best friend. Instead of enhancing your best facial attributes, they spotlight the narrow features of your face. 
  

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Consider if your face has sharp or soft angles 

As part of your new look, your facial angles are one of the more influential aspects. 

• Sharp angles: Square and heart-shaped faces feature sharper angles. When determining frames, think of contrasting shapes. For square-shaped faces, use curved frames to soften your face's sharper angles and give it a thinner appearance. For heart-shaped faces, round glasses draw the eyes away from the forehead to give the face a more symmetrical appearance. 
  
• Soft angles: Round and oval faces consist of softer angles. With round faces, go with square or cat-eye frames, as it can make your face appear smaller. You can achieve a similar effect with wider frames for heart-shaped faces. 
  

How to determine which colors match your skin tone 

Skin tone also plays a prominent role in the kind of the frames you select. Since you want to establish continuity in face shape, you'll need to choose a frame that's similar in color to your skin tone. Here are some tips to help you achieve this look: 

Warm skin tone

Skin tones of bronze, yellow, or golden invoke feelings of warmth. 

• Colors to avoid: Blue, bright pink, black and white frames contrast with warmer skin tones. 
  
• Best colors: Olive green, honey, beige and light tortoise are colors best fitting your skin tone. 
  

Cool skin tone

Blue and pink skin tones indicate a cool complexion. 

• Colors to avoid: Yellow, bright orange, and dark brown don't mesh well because they don't enhance your facial features. 
  
• Best colors: Black, silver, pink, purple or gray frames will be your facial allies. 
  

Read More: Pair Eyewear Review

Best eyeglass frames for your face shape 

Once you determine your face's shape, you'll want to decide which frame complements it the best. Here are the best fits for each type:

Round face: Aim for rectangular frames with bold angular lines. In turn, these can make your features look sharper.

Oval face: Oval faces are more versatile. Wide frames with a strong bridge enhance your facial features. 

Heart-shaped face: Find frames that toe the line between balancing a narrow chin and a larger forehead for a more symmetrical look. Frames with bottom-heavy lines and are slightly wider than your forehead will also help you achieve this. 

Square face: Rounder frames soften the angles of the face. If paired with a lens that is slightly wider than your cheekbones, you'll create more symmetry in the face. 

Diamond face: Cat-eye and oval eyeglasses enhance your cheekbones.

Consider your lifestyle 

Your glasses should also be practical for your daily activities. You might want a pair for gaming, long work days in front of an eye-searing screen or reading to reduce eye fatigue. And if you're active, having flexible frames that won't break when bent is a perfect match. 

Let your personality shine 

Ultimately, your frames should display your personality and style. You might want a fun, flirty pair for the weekends out with friends. And a more refined yet cute pair for the office -- it's fun but also signifies you mean business. While you can keep the considerations of this guide in mind, there are no rules. If the frame and color make you happy and confident, that's all that matters.