Understanding Fitzpatrick Skin Types and LED Lash Intensity Settings

When introducing LED technology into eyelash extensions, one of the most thoughtful advancements is adjustable intensity control.

You may have heard about the Fitzpatrick Skin Type Scale — a dermatological classification system that categorizes skin based on its response to UV exposure.

But what does that have to do with LED lash curing?

And why does Lash Plus include adjustable intensity settings?

Let’s explore the science.

What Is the Fitzpatrick Skin Type Scale?

The Fitzpatrick Scale classifies skin into six categories (I–VI) based on:

• Baseline skin tone
• Tendency to burn
• Tendency to tan
• Melanin concentration

Type	Skin Tone	Typical UV Response
I	Very fair	Always burns, never tans
II	Fair	Burns easily
III	Medium	Sometimes burns
IV	Olive	Rarely burns
V	Brown	Very rarely burns
VI	Deep brown	Almost never burns

At the core of this scale is melanin.

Why Melanin Matters in LED Lash Curing

Melanin is a natural chromophore — meaning it absorbs light.

Its absorption is strongest in:

• UV wavelengths
• Blue-violet visible light

Because LED lash systems emit light in the ~400 nm, melanin absorbs part of that energy before it reaches deeper tissue.

This creates an important principle:

Higher melanin levels = greater light absorption at the surface

That doesn’t mean darker skin is at risk — quite the opposite.

It means that light behaves differently depending on skin type.

How Light Interacts With Skin

When LED light hits skin:

1. A portion reflects
2. A portion is absorbed by melanin
3. A portion penetrates

The degree of penetration depends on:

• Wavelength
• Intensity
• Exposure time
• Melanin concentration

Since Lash Plus operates in the near-UVA/visible spectrum and uses very low total power output (~0.06 W), tissue penetration remains limited and controlled.

But from a curing perspective, surface absorption matters.

Why Adjustable Intensity Exists

The Lash Plus LED Tweezer includes multiple intensity levels.

Not because higher skin types are “more sensitive” — but because:

Different melanin levels alter light absorption dynamics.

In practical terms:

• Lighter skin types reflect and transmit slightly more light.
• Darker skin types absorb more surface energy.

Adjusting intensity ensures:

✔ Adequate radiant exposure reaches the adhesive
✔ Polymerization remains efficient
✔ Excess energy is not used unnecessarily

This is about precision, not risk mitigation.

Does Lower Intensity Change the Wavelength?

No.

This is an important clarification.

Reducing intensity does not change the wavelength emitted by the LED.

The LED chip emits within a fixed spectral (~400 nm). When you adjust intensity, you are modifying:

• Photon flux (number of photons per second)
• Irradiance (mW/cm²)

You are not changing:

• Spectral peak
• Nanometer distribution
• UV category

This means intensity adjustment affects energy delivery, not light type.

Irradiance vs Radiant Exposure in Practice

The curing threshold for adhesive depends on:

Radiant Exposure=Irradiance×Time

If melanin absorbs more energy at the surface, slightly higher irradiance may ensure sufficient radiant exposure reaches the adhesive interface in the same time window.

This allows artists to maintain:

• 1–2 second curing cycles
• Consistent bond strength
• Efficient workflow

Is This About Safety?

No — and this is important.

The Lash Plus system has already been independently tested under IEC 62471 and classified as RG0 (Exempt Risk Group), meaning it poses no photobiological hazard under intended use.

Intensity adjustment is not required for safety compliance.

It is an engineering feature designed for:

• Optical consistency
• Clinical adaptability
• Professional precision

Clinical Implications for Artists

Understanding skin-light interaction allows artists to:

• Make informed setting choices
• Optimize curing speed
• Maintain consistent retention across diverse clients

Rather than using one static output for all clients, you have controlled flexibility.

That’s professional-grade technology.

Why This Matters for the Industry

As LED lash technology evolves, the industry must move beyond simplistic comparisons to tanning beds or UV myths.

The real conversation is about:

• Optical physics
• Skin phototypes
• Energy modeling
• Standardized safety classification

Lash Plus integrates all of these considerations into its design.

Final Takeaway

The Fitzpatrick scale helps us understand how skin interacts with light.

LED intensity adjustment ensures that:

✔ Adhesive receives sufficient energy
✔ Curing remains efficient
✔ Energy use remains controlled
✔ Performance remains consistent across skin types

This is not guesswork.

It’s applied photophysics - 📄 Lash Plus LED Tweezer Engineering Whitepaper