Module
Skin analysis: how Facet scores your skin
Last updated: May 22, 2026
Facet's skin module scores the visual quality of your skin across five clinical parameters: homogeneity (uniformity of tone), melanin distribution, erythema (redness), pore density, and surface roughness. Every measurement maps to a peer-reviewed clinical reference, primarily Fink 2021 chromophore variance research. The output is a 0 to 10 score plus a ranked list of what to address first.
Why this matters
Perceived age is driven more by skin quality than by chronological age. A landmark Danish twin study (Christensen et al., BMJ 2023) found that perceived age, largely driven by skin homogeneity, was a stronger predictor of mortality than calendar age. Skin homogeneity also correlates strongly with health markers including immune function and pathogen load. Improving skin quality has compounding effects on both perceived attractiveness and how others assess your overall health.
Parameters measured
| Parameter | Units | Citation | Note |
|---|---|---|---|
| Skin homogeneity | sigma_L* (CIELAB lightness variance) | Fink 2021 | Lower variance scores higher; even tone signals health |
| Melanin distribution | sigma_L* in melanin-dominant zones | Fink 2021 | Captures patchy hyperpigmentation |
| Erythema | Mean a* in redness-dominant zones | Standard dermatology | Persistent redness drops score |
| Pore density | Pore count per cm² via LoG detection | Standard dermatology | Lower density scores higher |
| Surface roughness (Ra proxy) | High-pass spatial variance | Standard dermatology | Smoother skin scores higher |
What your skin score means
| Score band | Meaning |
|---|---|
| 8.0 to 10 | Excellent. Even tone, minimal redness, smooth texture. Routine maintenance only. |
| 6.5 to 7.9 | Good. Minor issues across one or two parameters. Targeted skincare can lift to excellent. |
| 5.0 to 6.4 | Average. Visible homogeneity, redness, or texture issues. Structured routine recommended. |
| 3.5 to 4.9 | Below average. Multiple parameters underperforming. Consider clinical consultation. |
| 0 to 3.4 | Significant skin issues across multiple parameters. Dermatologist consultation recommended. |
How to improve your skin score
- Establish a basic three-step routine first: gentle cleanser, broad-spectrum SPF 30+ daily, retinoid (start adapalene 0.1%) at night.
- Address erythema with niacinamide 4 to 5% serum if redness scores low. Avoid known triggers (alcohol, hot showers, harsh exfoliants).
- For homogeneity issues, prioritize daily SPF and consider vitamin C serum in the morning to slow pigmentation.
- Roughness improves with consistent gentle exfoliation (BHA 2% twice weekly, not more) and moisture barrier support.
- Document weekly with a controlled photo to track changes over months. Skin protocols compound; 8 to 12 weeks is the minimum window to evaluate.
- If pore density is the lowest-scoring parameter, consider professional consultation for in-clinic options (chemical peels, microneedling).
Frequently asked
Why does Facet's skin module score me differently than my dermatologist?+
Dermatologists evaluate skin clinically and qualitatively. Facet's skin module measures specific visual parameters (homogeneity, melanin, erythema, pore density, roughness) at the pixel level, then scores against published thresholds. The two approaches answer different questions. Facet provides a structured baseline you can take into a dermatology conversation.
Is Fitzpatrick skin type considered?+
Yes, indirectly. The melanin baseline is adjusted by the ethnicity setting you provide at scan time (7 categories supported). Fitzpatrick type informs the ethnicity-aware thresholds but is not currently scored as a separate parameter.
What about acne, wrinkles, and sagging?+
Facet has computed CV proxies for Merz wrinkle scale, GEA acne scale, and Sadick TTRS texture scoring. They are currently disabled in the skin aggregator because initial calibration over-triggered on normal faces. Re-enabling them is on the V3 roadmap pending recalibration against a larger dataset of real photos.
How long until my skin score improves?+
Skin parameters change slowly. Erythema can respond in 4 to 8 weeks with the right routine. Homogeneity and roughness take 8 to 16 weeks. Pore appearance changes take 12 to 24 weeks. Rescan monthly to track.