Updated: 5 November 2026
By Miolora team
UV rays are one of the main causes of dark spots and early wrinkles. A broad-spectrum sunscreen with SPF 30 or higher is the primary line of defense. A vitamin C serum applied in the morning before sunscreen may complement it, but it does not replace it.[2][6][8]
How Does the Sun Affect Your Skin?
Sunlight contains two main types of ultraviolet (UV) rays that affect the skin:
UVA Rays
UVA rays have a longer wavelength and reach the middle layer of the skin. They speed up the appearance of wrinkles and dark spots, and they pass through window glass. That is why protection still matters indoors near windows.
UVB Rays
UVB rays have a shorter wavelength and reach the outer layer of the skin. They are the main cause of sunburn, and window glass blocks them.
Excessive exposure to either type may lead to skin cancer, and a large share of UV rays reaches the skin even on cloudy days. That is why sunscreen needs broad-spectrum protection against both types.[1][2][3][4][5][6]
What Is Oxidative Stress?
When your skin is exposed to sun, pollution, and smoke, free radicals increase. Free radicals are active molecules that can affect collagen, elastin, and the skin barrier. Oxidative stress occurs when these molecules outpace the skin's ability to neutralize them. Over time, its effects build up gradually, and the skin may look dull, with dark spots and lines appearing.
The Role of Antioxidants
Antioxidants are ingredients that help counter the effects of free radicals. They are a complementary addition to sunscreen, not a replacement for it.
Vitamin C
One of the most well-known antioxidants in skincare. It is applied in the morning after cleansing and before sunscreen, and it helps reduce the signs of aging and dark spots.
ANUA Green Lemon Vita C Blemish serum 20g
A serum with vitamin C from green lemon extract that helps brighten and even skin tone for a radiant complexion.
Key actives: Vitamin C, Lemon Extract, Allantoin
Torriden CELLMAZING Brightening Ampoule
A Vitamin C ampoule designed to improve skin tone and enhance overall radiance, with antioxidant protection.
Key actives: Vitamin C, Niacinamide, Adenosine
Arencia Vitamin C Booster Shot Face & Eye Cream Moisturizer
A cream-gel moisturizer for the face and under-eye area that helps brighten dull skin and improve glow.
Key actives: Vitamin C, Glutathione, Niacinamide
Vitamin E
An antioxidant that supports skin hydration. It is often used together with vitamin C in the same formulations.
Ferulic Acid and Resveratrol
Plant-based antioxidants added to some formulations to support their stability and antioxidant properties.
Niacinamide
A form of vitamin B3 that supports the skin barrier and helps improve the appearance of uneven skin tone. For more, read the Niacinamide Guide.[8]
Sunscreen in Brief
Choose a broad-spectrum sunscreen with SPF 30 or higher, apply it every day to exposed skin, and reapply about every two hours and after swimming or sweating. It goes on after your skincare products and before makeup. To compare types by skin type, read the Korean Sunscreen Guide for Oily Skin or browse the Sun Protection Collection.[6][7][9]
For oily skin
Beauty of Joseon Relief Sun Aqua-Fresh 50ml
A lightweight sunscreen that provides strong SPF50+ PA++++ defense against UVA/UVB rays.
Key actives: Chemical UV filters, Rice, Panthenol (vitamin B5)
Anua Invisible Matte Finish Sunscreen (50 ml)
A lightweight sunscreen that delivers a long-lasting, weightless matte finish.
Key actives: Heartleaf (Houttuynia cordata)
For dry skin
Beauty of Joseon Relief Sun: Rice + Probiotics 50ml
A lightweight sunscreen that offers broad-spectrum SPF50+ PA++++ protection against UVA and UVB rays.
Key actives: Chemical UV filters, Niacinamide, Rice
COSRX Aloe Soothing Sun Cream SPF50+ PA+++
A sunscreen that helps protect against sun damage while soothing redness and irritation.
Key actives: Chemical UV filters, Mineral UV filters, Aloe Extract
For sensitive skin
SOME BY MI TRUECICA Mineral Calming Tone Up Suncream (SPF50+ PA++++)
A lightweight mineral sunscreen that helps protect against UVA and UVB rays while soothing irritation and redness.
Key actives: Mineral UV filters, Niacinamide, Adenosine
Morning Routine for Sun and Antioxidant Protection
- A gentle cleanser that suits your skin type.
- A vitamin C serum or an antioxidant blend.
- A moisturizer that supports the skin barrier.
- A broad-spectrum sunscreen with SPF 30 or higher.
Alongside sunscreen: sunglasses with full UV protection, a wide-brimmed hat, and limiting direct exposure during peak sun hours.[6][8][9][10]
Protection with Miolora
Sun protection is a set of steps that work together. From Miolora, choose an antioxidant serum, a moisturizer, and a sunscreen that suit your skin, and make protection a consistent part of your routine.
FAQ
Do I really need to wear sunscreen every day?
Yes, if you go outside, apply it to all exposed skin every day, even on cloudy days.[5][7]
What's the difference between UVA and UVB?
UVA reaches a deeper layer of the skin, speeds up wrinkles and dark spots, and passes through window glass. UVB is the main cause of sunburn.[1][2][3]
Does vitamin C protect against the sun?
No, vitamin C is not a substitute for sunscreen and has no SPF rating. It is a complementary step applied before sunscreen.[8]
Can I use vitamin C with sunscreen?
Yes, apply it in the morning after washing your face and before sunscreen.[8][9]
Do I need to reapply sunscreen when I'm indoors?
No, reapplying every two hours is for time spent outdoors. If you sit by a window where sunlight comes in, UVA rays pass through the glass, so protection still matters there.[2][7]
Does oily skin need sunscreen?
Yes, all skin types need protection. Choose a lightweight formula that suits you, and see the Sunscreen Guide.
Sources
- UVB rays have a short wavelength that reaches the outer layer of the skin; UVA rays have a longer wavelength that can reach the middle layer (the dermis). — U.S. FDA
- UVA rays can prematurely age skin, causing wrinkles and age spots, and can pass through window glass. — American Academy of Dermatology
- UVB rays are the primary cause of sunburn and are blocked by window glass. — American Academy of Dermatology
- Overexposure to either UVA or UVB can lead to skin cancer. — American Academy of Dermatology
- Even on cloudy days, up to 80% of the sun's UV rays can get through the clouds. — American Academy of Dermatology
- Broad-spectrum sunscreens protect against UVA and UVB; dermatologists recommend SPF 30 or higher, which blocks 97% of UVB rays. — American Academy of Dermatology
- Apply sunscreen every day to skin not covered by clothing when you will be outside, and reapply about every two hours or after swimming or sweating. — American Academy of Dermatology
- Apply vitamin C after washing the face in the morning, before sunscreen; it can reduce skin aging and dark spots. — American Academy of Dermatology
- Put sunscreen on after other skin care products and beneath makeup. — American Academy of Dermatology
- Protect yourself with sunglasses rated for 100% UV protection, a wide-brim hat and broad-spectrum sunscreen, even in cloudy weather. — U.S. FDA
