Wayfarers, like any other sunglasses, should fit comfortably and securely on your face. Here are some guidelines to ensure a proper fit for Wayfarers:

1. Width: The width of the sunglasses should match the width of your face. The temples (arms) should extend straight back and not press tightly against your temples or bend outward too much.
2. Nose bridge: The nose bridge should sit comfortably on your nose without sliding down or digging into the skin. Make sure the fit is snug but not overly tight. Adjustable nose pads, if present, can help customize the fit.
3. Temple length: The temples should extend past your ears and fit snugly without causing any discomfort or pressure. They should not dig into your temples or slide off easily.
4. Frame alignment: The frame should be level and aligned with your face. Check that the Wayfarers sit straight and do not tilt to one side. Adjust the temples if needed for proper alignment.
5. Eye coverage: The lenses should adequately cover your eyes and provide sufficient protection from sunlight and glare. They should not be too small, leaving your eyes exposed to UV rays, or too large, obstructing your vision or facial features.

Remember, everyone's face shape and size are unique, so what fits one person perfectly may not suit another. It's essential to try on the sunglasses and assess the fit in person. If purchasing online, consider the seller's return policy in case the fit is not suitable.

Properly fitting sunglasses not only provide eye protection but also ensure comfort and enhance your overall style. If you have concerns about the fit or want personalized recommendations, visiting an optician or an authorized retailer can be helpful to find the perfect fit for your face shape and size.