Crow's feet and forehead lines: why they appear first

If you ask someone where they saw their first wrinkle, the answer is almost always the same: at the corners of the eyes or on the forehead. It is no coincidence. These two areas bring together almost all the factors that make skin show lines early: thin or highly exposed skin, muscles that work all day, direct sun and habits that make them work even harder.

Understanding why helps you know what is worth doing and, above all, what not to do. The forehead, in particular, hides a trap: in some people the lines are the sign of a muscle compensating for the weight of the eyelids, and treating them without assessment can worsen the look.

Crow's feet: thin skin over a tireless muscle

Crow's feet are the lines that radiate from the outer corner of the eyes, in a fan, and become more pronounced when smiling. There are several reasons why they are often the first to appear.

1. The thinnest skin on the face

The skin of the eyelids and eye area is the thinnest on the face. Studies measuring facial skin thickness place the eyelid at the thinnest end of the scale, several times thinner than the skin of the forehead or chin (Ha et al., 2005). It also has:

• Little fat underneath to cushion it.
• Few sebaceous glands, which makes it drier and more vulnerable to dehydration.
• A thinner dermis, with less reserve collagen.

Thin skin folds more easily and keeps the crease sooner.

2. A muscle that never stops

Beneath this skin lies the orbicularis oculi, a circular muscle that closes the eyelids. It contracts:

• With every blink. At rest we blink, on average, about 15 to 20 times a minute, that is, thousands of times a day (Bentivoglio et al., 1997).
• With every genuine smile. The spontaneous smile (the so-called Duchenne smile) involves precisely the contraction of this part of the muscle, which lifts the cheeks and crinkles the corners of the eyes (Ekman et al., 1990).
• Whenever you squint, because of light, a screen or poorly corrected vision.

The lateral fibres of the muscle pull the skin towards the centre of the eye; the skin folds perpendicular to that movement, forming the rays of the "crow's feet".

3. Direct sun, from the front and the side

The outer side of the eyes receives sun from the front and the side, and is often forgotten when applying sunscreen, for fear that it will sting the eyes. The result is thin, very active and poorly protected skin: the perfect combination for photoageing.

4. Friction

Rubbing the eyes (from allergy, tiredness or habit) and removing make-up forcefully repeatedly stretch skin that has little capacity to recover.

Crow's feet have a dynamic component (appearing when smiling) and, over time, a static component (visible at rest). The fine lines around and under the eyes are often a mixture of fine wrinkles and dehydration lines. If you want to understand the difference, see Fine lines, expression lines and wrinkles: they are not the same thing.

Forehead lines: the only muscle that lifts the eyebrows

The horizontal lines of the forehead result from contraction of the frontalis muscle, a broad sheet of muscle that runs from the hairline to the eyebrows. It has one important particularity: it is the only muscle that lifts the eyebrows. All the other muscles in the area pull them down or towards the centre.

Why they appear early

• Expressiveness. Raising the eyebrows goes with surprise, attention, emphasis when speaking, doubt. Some people do it constantly, almost without realising.
• Direct link to the skin. The frontalis has no bony attachment at the bottom: it inserts into the skin of the eyebrows. When it contracts, it directly wrinkles the forehead skin into horizontal folds.
• Sun exposure. The forehead is a broad surface, facing up and forwards, that catches the sun directly. In people with a receding hairline or short hair, even more so.
• Thicker skin, but highly exposed. The skin of the forehead is thicker than that around the eyes, but cumulative sun exposure cancels out that advantage.

The "compensating" forehead

Here is the nuance that matters most. With age, the eyebrows tend to descend and the skin of the upper eyelids develops excess (dermatochalasis). In some people, there is also an eyelid that droops because of weakening of the muscle that lifts it (ptosis). In these cases, the frontalis contracts almost permanently, without the person noticing, to lift the eyebrows and move the weight of the eyelid out of the field of vision.

The result is deeper forehead lines and a forehead that is always "straining", often accompanied by tiredness at the end of the day. Signs that suggest this:

This has a very important practical consequence, which we will see further on: relaxing the frontalis in these people can lower the eyebrows and worsen the feeling of heaviness in the eyes.

The line between the eyebrows and other factors that bring it on earlier

The third area that tends to mark early is the glabella, between the eyebrows. The vertical lines (sometimes called "11 lines" or "frown lines") result from the corrugator and procerus muscles, which draw the eyebrows together and down when we frown: from concentration, worry, irritation or to see in the sun. Because they convey an expression of tiredness or anger, they are often the ones that bother people most.

What makes these lines appear sooner

The good news is that several of these factors are modifiable, and some at no cost at all.

Home care for these areas

Sunscreen up to the edge of the eyes

It is the most effective measure and the most forgotten (Hughes et al., 2013). Some practical suggestions:

• Apply sunscreen to the whole face, including the temples, the outer side of the eyes and the eyelids, with the ring finger and gentle dabbing.
• If your sunscreen stings your eyes, try formulas with mineral filters (zinc oxide, titanium dioxide) or a stick for the eye area.
• Do not forget the forehead up to the hairline, and any receding hairline.

Sunglasses and corrected vision

Sunglasses with UV filters reduce radiation on the skin around the eyes and, above all, stop you squinting. Wraparound models also protect the side. If you find yourself frowning to read or see into the distance, an ophthalmology or optometry appointment is worthwhile.

Retinoids with gradual adaptation

Topical retinoids are the actives with the best evidence for fine wrinkles, and the eye area and forehead benefit from them (Kafi et al., 2007). But the skin around the eyes is easily irritated:

• Start with a gentle retinol or a product formulated for the eye area.
• Apply two to three nights a week and increase gradually.
• Keep a distance from the edge of the eyelids and the lash line.
• If there is redness, stinging or flaking, reduce the frequency.
• Do not use in pregnancy or when breastfeeding.

Hydration and barrier

Because the skin around the eyes has few sebaceous glands, it benefits from a moisturiser with humectants and ingredients that repair the barrier. Many of the fine lines under the eyes improve with this alone. A specific eye cream is not essential, but it may be useful if it is better tolerated than your face cream. See Eye creams: what to expect.

Habits that help

• Remove eye make-up with a suitable product, letting it work instead of rubbing.
• Treat allergies that lead to eye rubbing.
• Take breaks from the screen, adjust the brightness and the text size.
• Do not smoke.

What is not worth it

• Anti-wrinkle adhesive strips on the forehead or around the eyes: they may reduce frowning while in use, but there is no evidence of a lasting effect.
• Facial exercises: the evidence is scarce and, in areas of dynamic lines, more contraction does not seem logical.
• Products that promise to "relax the muscles" topically: there is no evidence of an effect comparable to a medical treatment.

Treatments: what exists and why the forehead calls for assessment

When home care is not enough, there are options in the clinic. The choice depends on whether the lines are mainly dynamic (only with movement) or already static (visible at rest).

For dynamic lines

Botulinum toxin temporarily relaxes muscles and softens the lines they cause. It has an approved indication for the lines between the eyebrows, crow's feet and, for some products, forehead lines. In Portugal it is a prescription medicine and its administration is a medical act. The effect sets in within a few days and usually lasts 3 to 4 months.

For lines that are already set

• Chemical peels, mainly for fine lines and the texture of the eye area and forehead.
• Microneedling and collagen-stimulating technologies, with variable results.
• Hyaluronic acid filler in selected static wrinkles, by a doctor, with special care on the forehead and the glabella, which are areas of vascular risk.

The "compensating" forehead: why it is not treated blindly

Remember the forehead that works to hold up heavy eyelids? In these people, relaxing the frontalis muscle removes the only support for the eyebrows. The result may be:

• Lower eyebrows and a heavier-looking appearance of the eyes.
• A greater feeling of heaviness in the eyelids, sometimes with difficulty seeing the upper part of the visual field.
• A more tired expression than before the treatment.

Descent of the eyebrow and eyelid is described as a known undesirable effect of these treatments. That is why a good assessment looks at eyebrow position, excess eyelid skin and how the forehead behaves with the eyes closed. In some cases, the appropriate response is not to treat the forehead, but to assess the eyelids, possibly with an ophthalmologist or plastic surgeon.

At Luxmed, the first wrinkles begin with an assessment: which lines you have, whether they are dynamic or static, and what is causing them. The plan combines home care and skin treatments, with medical referral when indicated.

This article is for information purposes and does not replace a medical consultation. The results of any treatment vary from person to person.

Frequently asked questions