1 What is the problem?
Hyperpigmentation means patches of skin darker than their surroundings because of extra melanin — e.g. sun spots (solar lentigines), freckles, and melasma (hormone- and sun-related patches, common on the cheeks).
2 The science
Very short pulses (nanoseconds or picoseconds) hit melanin granules so fast that they shatter from the pressure wave instead of just heating. The fragments are cleared by the body’s immune cells. Melasma is tricky: too much heat can trigger rebound darkening, so gentle low-energy “laser toning” is used.
3 Key points to remember
- Shorter pulses = less heat spreading to nearby skin
- Superficial pigment responds faster than deep pigment
- Sunscreen is essential — UV light makes melanin return
- Melasma needs medicines + lasers; lasers alone rarely cure it
4 What happens during treatment
- 01
Pigment depth is checked (often with a Wood’s lamp)
- 02
Eyes are protected with goggles
- 03
Laser passes; spots may darken briefly
- 04
Darkened spots flake off over 1–2 weeks
5 Possible risks
Post-inflammatory hyperpigmentation (darkening) or hypopigmentation (light spots), especially in darker skin. Correct settings, skin cooling and experienced hands reduce these risks.
Did you know? A picosecond is one-trillionth of a second — light travels only about 0.3 mm in that time.