What kinds of medical light are there?

• 1. Red light ‌ : red light is widely used in dermatology. Its long wavelength can penetrate deep into skin tissue and play a repairing role in skin, such as improving allergic reactions and reducing the formation of acne scars ‌.
• ‌2. Blue light ‌ : blue light has a short wavelength, mainly acts on the skin surface, has the function of inhibiting propionibacterium acnes, antibacterial and anti-inflammatory, and inhibiting sebaceous gland oil secretion. It is often used in the treatment of acne and other superficial skin problems ‌.
• ‌3. Ultraviolet ‌ : ultraviolet therapy can prevent and cure diseases by artificial irradiation of ultraviolet light. It has the functions of anti-inflammatory, analgesic, accelerating tissue regeneration, regulating nerves, desensitizing and enhancing immune function. Ultraviolet light is often used in dermatology to treat skin diseases such as vitiligo and psoriasis ‌. However, it should be noted that there are also certain contraindications in UV treatment, such as malignant tumors, lupus erythematosus, photosensitive dermatitis, bleeding tendency, etc. ‌.
• ‌4. Infrared ‌ : infrared therapy produces warming effect by irradiating the human body, promotes blood circulation, enhances tissue cell vitality and regeneration ability. In the medical field, infrared ray is often used to treat chronic inflammation, sprain, muscle strain, peripheral nerve injury, fracture, tenosynovitis, postoperative adhesion, etc ‌. The depth of infrared penetration varies according to wavelength. Shortwave infrared can reach the dermis and subcutaneous tissue, while longwave infrared can only reach the superficial layer of the skin ‌.
• ‌5. Laser ‌ : Laser therapy uses the light energy generated by laser radiation to treat diseases. It has anti-inflammatory, analgesic and tissue regeneration functions. In medical treatment, laser therapy can be used to treat wound infection, contusion, neuritis and periarthritis of shoulder ‌.

The difference between red and blue light?

• ‌ wavelength difference ‌ : Red light has a longer wavelength, usually between 620 nm and 760 nm ‌, while blue light has a shorter wavelength, usually between 400 nm and 500 nm ‌. This difference in wavelength determines how deep they penetrate the skin and where they act.
• ‌ penetration and energy ‌ : Because red light has a longer wavelength, it has stronger penetration and can penetrate deeper into the skin tissue ‌3. Red light mainly emits heat energy, which stimulates mitochondria in cells, increases energy metabolism of cells, and promotes cell regeneration and repair ‌. Due to the length of the wave, the penetration of blue light is relatively weak. It mainly acts on the skin surface. The energy emitted by blue light is electromagnetic energy, which can destroy the cell membrane of bacteria and inhibit the growth and reproduction of bacteria ‌.
• ‌ Functions and scope of application ‌ : red light treatment can penetrate deeper skin tissue, play a role in skin repair, such as repair wound, improve allergic reaction, reduce the formation of acne scar, etc. It is suitable for a variety of skin problems, such as wrinkles, relaxation, pigmentation, burns, wounds, etc ‌. The blue light treatment mainly achieves the effect of killing propionibacterium acnes, has the effect of anti-inflammatory, sterilization, sedation, but also can purify the skin, effectively inhibit the secretion of sebaceous glands and oil, prevent acne recurrence, mainly used for the treatment of acne and other superficial skin problems ‌.
• ‌ Therapeutic effect and duration ‌ : red light's therapeutic effect is relatively mild and long-lasting, it takes several treatments to see the obvious effect, but once the effect, usually can be sustained for a long time, about three years ‌. The effect of blue light treatment is relatively quick, but frequent treatment may be required to maintain the effect, lasting about two years ‌. Meanwhile, blue light treatment for acne may cause side effects such as dry skin ‌2.
• ‌ safety ‌ : In general, red and blue light are safe when used correctly. However, because the wavelength of blue light is short and the energy is relatively high, it may cause certain damage to the eyes, and protective glasses are needed when using blue light treatment. Red light is less harmful to the eyes ‌.