Can you change your canthal tilt?

Canthal tilt is the slope of the line from the inner corner of the eye to the outer corner. The outer corner sits where the ligament attaches to bone, and the skull decides where that bone is. That makes the tilt structural, in the same category as the spacing of the eyes or the width of the jaw. It is largely inherited, as is canthal tilt genetic? explains, and it settles once facial growth is finished.

• Brow tail. A tail that hangs low over the outer corner drags the eye down visually. Keeping it tidy and level is grooming convention rather than research, but it is cheap and reversible.
• Sleep. A study photographing the same people rested and sleep-deprived found the tired faces were judged to have more hanging eyelids and swollen eyes. The eye reads flatter; the bone has not moved.
• Puffiness. Swelling at the lower outer corner fills in the line. Salt, alcohol, allergies and short sleep all add to it.
• Eyeliner. A wing extended upward past the outer corner fakes a positive tilt. That is what it is designed to do.
• Photo angle. A camera slightly above eye level with the chin down makes eyes read upturned; a camera below does the opposite. Neither is your tilt.

Most people who want a positive tilt really want a rested, well-groomed version of the eyes they have, and that is achievable. Forums also tend to overrate the trait: is a negative canthal tilt bad? covers what the research actually says.

Take one honest photo: camera at eye level, head straight, arm's length away, face relaxed. The canthal tilt test reads it and gives a band for each eye, positive, slightly positive, neutral or negative. Slightly positive is the ordinary adult case. Retake the photo after a good night's sleep and with the brow tidied, and you can see how much of the reading was presentation.