Scientists test sunscreens against visible light on three skin types

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * To be enrolled in this study, all subjects must satisfy all the following criteria at study entry: 1. Healthy female or male volunteer from 18 to 50 years old 2. Caucasian Skin type III-IV according to the Fitzpatrick classification OR Asian Skin type III-IV (chinese population) according to the Fitzpatrick classification OR Darker Skin type VI according to the Fitzpatrick classification 3. Average ITA° (Individual Typologic Angle calculated value) on the back between 24° and 36° at screening and inclusion visits with an allowed difference of ± 2° between screening and inclusion visits, for Caucasian volunteers OR Average ITA° (Individual Typologic Angle calculated value) on the back between 24° and 36° at screening and inclusion visits with an allowed difference of ± 2° between screening and inclusion visits, for Asian volunteers OR Average ITA° (Individual Typologic Angle calculated value) on the back less than -30° at screening and inclusion visits with an allowed difference of ± 2° between screening and inclusion visits, for Darker skin volunteers 4. Uniform skin color over the four zones (difference in ITA° between each zone should not be more than 4°) 5. Absence of freckles, naevi, hypo or hyper pigmented regions, hairs and marks of bronzing on the investigational area on the back 6. Female subject of childbearing potential, who is not sexually active, or using an effective contraceptive method\* for at least one month before the beginning of the study, and throughout the study or menopausal female (with absence of menstruations for less than one year) or post-menopausal female (with absence of menstruations for more than one year) \*Effective contraceptive methods: sexually active female of childbearing potential should either be surgically sterile (oophorectomy, hysterectomy or tubal ligation), or should use a medically accepted contraceptive regimen: systemic contraceptive (oral, implant, injection), diaphragm or cervical cap with intravaginal spermicide, intravaginal device, intrauterine device (IUD), condom with spermicide 7. Female of childbearing potential or menopausal female (with absence of menstruations for less than one year) willing to undergo urine pregnancy test 8. Subject willing and able to fulfil the study requirements and schedule 9. Subject informed about the study objectives and procedures, and able to understand them 10. Subject who has given written informed consent Exclusion Criteria: * If any following non-inclusion criterion applies, the subject must not be included in the study: 1. Subject who is pregnant or lactating or who is planning to become pregnant during the study 2. Subject with BMI \> 30 except if, according to the investigator's judgement, the subject is able to follow the study procedure without compromising his/her health 3. Having planned UV exposure of the investigational area (sunlight or sunbeds) throughout the study 4. Having used sunbeds or had excessive sun exposure of the investigational area within the 3 months before inclusion 5. Having sunburn (erythema) on the back 6. Dermatological disorders affecting the investigational area (presence of naevi, freckles, excess hair or uneven skin tones, vitiligo, photo-dermatological problems) 7. History of skin cancer 8. History of abnormal response to sun 9. Presence of recent suntan (according to Investigator opinion) or photo-test marks 10. History of allergy, hypersensitivity, or any serious reaction to any cosmetic product 11. Any concomitant medical condition that may interfere with the study conduct in the opinion of the investigator 12. Having used within the month before inclusion any systemic medication for more than 5 consecutive days (e.g. steroidal and non-steroidal anti-inflammatory drugs, corticoids, insulin, antihistamines, antihypertensive, antibiotics such as quinolone, tetracycline, thiazides, fluoroquinolones) 13. Having used within the month before inclusion any medication known to cause abnormal responses to UV exposure (e.g. vitamin A derivative, psoralen, aminolevulinic acid derivatives, etc.), or having planned to use these medications during the study 14. Having used within the 3 months before inclusion any depigmenting / whitening or pro-pigmenting topical treatments, or any systemic treatment that would interfere with the study assessments (anti-inflammatory drugs, corticoids, retinoids, hydroquinone, etc.) or having planned to use these treatments during the study 15. Having used, within the past 6 months, any physical treatment including laser or phototherapy (PUVA, IPL, PDT…) on the investigational area, or having planned to use these treatments during the study 16. Having planned to perform intensive sport (\> 5 hours per week) or to swim or to practice hammam/sauna during the study 17. Subject who declares to be deprived of freedom by administrative or legal decision 18. Subject who cannot be contacted by telephone in case of emergency 19. Subject having participated within the 30 days before inclusion or currently participating in another clinical study