Studies that have investigated the causes of ocular skin sensitivity, or more generally to say, reactive eye skin or intolerant eye skin.

1. Environmental Factors:
A study published in the Journal of Allergy and Clinical Immunology examined the impact of environmental allergens on ocular health. The study found that individuals with ocular allergies had a higher prevalence of positive skin tests to various allergens compared to those with nasal allergies, indicating a distinct population with heightened cutaneous reactivity.

2. Chemical Irritants:
Research featured in Cosmetics journal analyzed the presence of allergens in cosmetic products designed for sensitive skin. The study revealed that fragrances were the most common allergens, followed by skin-conditioning agents, surfactants, and preservatives. Notably, fragrances like linalool and benzyl alcohol were frequently used, highlighting the potential for these chemicals to cause skin sensitivity, including eye skin sensitivity.

3. Age and Skin Barrier Function:
An article in the Journal of Investigative Dermatology discussed the susceptibility of periorbital skin to aging and environmental factors. The study emphasized that the delicate nature of the periorbital area makes it particularly prone to signs of aging, such as dryness, hyperpigmentation, and loss of density, which can contribute to increased skin sensitivity.

4. Allergic Reactions:
A review in Allergy, Asthma & Clinical Immunology provided a contemporary look at allergic conjunctivitis, noting that allergic eye disease affects approximately 40% of the population and is increasing in prevalence. The review highlighted that ocular allergy symptoms can significantly impact quality of life and discussed various treatment options.

5. Inappropriate Cleansing Practices:
A study in the Dermatitis journal analyzed the effects of improper cleansing on facial skin, finding that excessive or inappropriate cleansing can disrupt the skin’s natural barrier. This leads to transepidermal water loss, making the skin around the eyes drier and more prone to irritation and sensitivity. The study highlighted that harsh cleansers with high pH or abrasive ingredients were especially detrimental to sensitive skin, including the delicate periorbital area.

6. Dry Indoor Air and Air Conditioning:
An article in the International Journal of Cosmetic Science examined how indoor environmental factors, such as air conditioning, contribute to skin dryness, particularly around the eyes, where the skin is thinner. Dry air accelerates moisture loss, leading to skin dehydration and a compromised barrier, which can trigger irritation and sensitivity around the eyes.

7. Frequent Use of Makeup and Makeup Removers:
A study in Contact Dermatitis journal observed that frequent use of eye makeup, especially waterproof products, and makeup removers can cause irritation. The study pointed out that many removers contain solvents or alcohol-based ingredients, which can dry out the skin and damage the periorbital area’s protective layer, leading to redness, dryness, and sensitivity.

8. Blue Light Exposure:
Studies, including one published in Free Radical Biology and Medicine, have shown that blue light (high-energy visible light) emitted from screens (like those on computers, phones, and tablets) can generate reactive oxygen species (ROS) in skin cells. This oxidative stress can damage the skin’s collagen and elastin, accelerating aging and making the skin more sensitive. The thin skin around the eyes is especially vulnerable to these effects, potentially leading to dryness, fine lines, and increased reactivity.
An article in the Journal of Cosmetic Dermatology examined the effects of long-term blue light exposure on skin hydration. It noted that blue light can disrupt the skin's natural hydration balance by affecting its barrier function, resulting in dryness and irritation. For the delicate periorbital area, prolonged exposure can exacerbate dryness and increase sensitivity to environmental irritants.
Another study in Chronobiology International indicated that blue light exposure from screens can disrupt the circadian rhythm, affecting nighttime skin repair. Since the skin around the eyes is thin and regenerates more slowly, the lack of proper nighttime recovery can lead to increased sensitivity and signs of aging.

9. Contact Lenses:
Studies, such as one in the British Journal of Ophthalmology, have found that contact lenses can cause dryness, irritation, and increased sensitivity around the eyes due to several factors. These include reduced tear film stability and mechanical friction from the lenses, which may lead to a compromised eye surface and periorbital skin dryness. Wearing contact lenses for extended periods can also reduce oxygen flow to the cornea, leading to dryness and discomfort around the eyes.
Some research, like an article in Contact Lens & Anterior Eye, highlights that contact lens cleaning solutions can contain preservatives or chemicals that may cause irritation or allergic reactions in sensitive individuals. For instance, solutions with preservatives like benzalkonium chloride can increase skin sensitivity in the periorbital area, leading to redness, itching, and irritation around the eyes.

10. False Eyelashes and Adhesives:
A study in the Journal of Cosmetic Dermatology noted that adhesives used for false eyelashes often contain irritants such as formaldehyde or cyanoacrylate. These chemicals can cause contact dermatitis or allergic reactions, particularly around the thin and sensitive skin of the eyelids. Regular use of adhesives can weaken the skin barrier, leading to chronic sensitivity and irritation.

The American Journal of Ophthalmology reported that both contact lenses and false eyelashes can increase the risk of bacterial buildup if not properly cleaned or maintained. This buildup may lead to conditions like blepharitis (inflammation of the eyelids), which can exacerbate skin sensitivity, redness, and irritation around the eyes.