Can sunscreen stop hidden skin damage from blue light?

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

Inclusion Criteria: 1. Fitzpatrick Skin Type III or IV targeting to complete at least 5 subjects in each skin type. 2. Has ITA (calculated per the method defined in ISO24442:2022) of 10.00° to 41.00° for each test site (average value from subsites 1 and 7 per site) , with no variation in ITA° greater than 5° between test sites (having uniform skin color over the whole test area). 3. Agrees to receive artificial sunlight (UV) exposure on the back. 4. Agrees to refrain from sun exposure on the back, use of tanning beds, and self-tanning lotions, creams, or sprays until the completion of the study. 5. Generally in good health based on medical history reported by the subject. 6. Able to read, write, speak, and understand English. 7. Has signed the Consent for Photograph Release and ICD including Health Insurance Portability and Accountability Act (HIPAA) disclosure. 8. Intends to complete the study and is willing and able to follow all study instructions. Exclusion Criteria: 1. Has known allergies or adverse reactions to latex, common topical skincare products, UV light, or ingredients in the ISMs. 2. Has a history of abnormal responses to sunlight or UV radiation. 3. Has been instructed by a physician, pharmacist, or health professional to avoid sunlight because of a medical condition and/or because of drug contraindications. 4. Has a history of photosensitivity (a reaction to sunlight) disorders (including solar urticaria \[hives\], phototoxicity, photo-allergy, polymorphous light eruptions). 5. Is regularly taking a medication with photosensitizing potential, such as high blood pressure medication, acne medications (e.g., Accutane), certain psychiatric medications (e.g., Thorazine, tricyclic anti-depressants), certain antibiotics (e.g., Cipro, tetracycline), antihistamines (e.g., Benadryl), Levulan, or Psoralen. 6. Is regularly taking other medication that could affect the results of the study (e.g., corticosteroids, steroidal or nonsteroidal anti-inflammatory drugs \[NSAIDs\], antihypertensive drugs, steroid inhalers, drugs that induce skin coloring, etc.). Low dose aspirin (≤81mg per day) is acceptable. 7. Has used a tanning bed/lamp, has had extended sun exposure of the test area (the lower back), or has participated in a UV exposure study within 4 weeks before Visit 1. 8. Has a concurrent illness, a medical history of a disease/condition, or a pre-existing/dormant dermatologic condition (e.g., psoriasis, rashes, eczema, seborrheic, severe excoriations, skin infection \[fungal, bacterial, or viral\], etc.) that could interfere with the outcome of the study or increase health risk to the subject, as determined by the PI or designee. 9. Via visible light and Wood's lamp evaluation: presence of sunburn, suntan, scars, tattoos, active dermal lesions, nevi, blemishes, moles, excessive tan spots from prior sunscreen testing, excessive hair, or uneven skin tone on the test area (back) that might interfere with the study. 10. Has a history of immunosuppression/immune deficiency disorders (including HIV infection, AIDS, multiple sclerosis, Crohn's disease, rheumatoid arthritis), organ transplant (heart, kidney, etc.), and/or undergoing radiation or chemotherapy as determined by study documentation. 11. Has self-reported Type 1 or Type 2 diabetes or is taking insulin or another anti-diabetic medication. 12. Is taking a medication that would mask an Adverse Event (AE) or confound the study results, including: * Non-steroidal anti-inflammatory drugs within 5 days before Visit 1.\* * Antihistamines within 14 days before Visit 1.\* * Antibiotics within 16 days prior to Visit 1.\* * Immunosuppressive drugs or steroidal drugs within 2 months before Visit 1.\* * Systemic or topical medication that is known to alter responses to UV radiation.\* \* If an individual is taking one of these medication types, the individual is not considered eligible at screening. However, if a subject begins using one of these medications during the study, the PI should be consulted to consider the impact of the specific medication on subject safety and/or the study results. 13. Has a personal or family history of skin cancer. 14. Has skeletal protrusions and/or extreme areas of curvature in the test area. 15. Is self-reported to be pregnant, lactating, or planning to become pregnant during the study or within 30 days of study completion. 16. Has a history of or a concurrent health/other condition/situation which may put the individual at significant risk, confound the study results, or interfere significantly with the individual's participation in the study . 17. Has shaved, waxed, and/or used any hair removal method on the test area (back) within 2 weeks before visit 1. 18. Has applied any leave on product(s) on the test area within 24 hours before Visit 1. 19. Is simultaneously participating in any other clinical study or has participated in any product-use study within 30 days prior to Visit 1. 20. Has started a long-term medication within the last 2 months. 21. Has started hormone replacement therapies (HRT) or hormones for birth control or menopause less than 3 months before study enrollment or who plan on starting, stopping, or changing doses of HRT or hormones for birth control during the study. 22. Is an employee/contractor of the PI, Study Site, or Sponsor or immediate family member of the PI, Study Site Personnel, or Sponsor