Eyeliner is one of the most common eye cosmetics. The main ingredients are titanium oxide, pigment, grease and preservative. The user will apply the eyeliner to the eyelid and eyelash. With the blinking again and again, the components of the eyeliner may enter the tear film and continue to act on the eye surface. Therefore, the investigators suspect that the use of eyeliner may be an important factor leading to dry eye disease. In order to explore the relationship between the use of eyeliner and dry eye disease, the investigators plan to collect eye surface characteristic data of the two groups of people who use eyeliner and who do not use it.Then use Raman analysis to explore whether the use of eyeliner will lead to changes in tear composition.The investigators intend to analyze the difference of tear composition between the two groups to understand the relationship between the change of tear composition and tear film stability.So that the investigators can identify the risk factors of dry eye disease, and provide basis for prevention and early treatment.

The investigators will include the population according to the inclusion criteria and exclusion criteria.The subjects in the eyeliner group and the control group filled in the survey to score the ocular surface disease index. Tear secretion test and sodium fluorescein staining are conducted in the eyeliner group and the control group, and the results are recorded. The intraocular pressure of the two groups is measured and recorded. Dry eye analysis is conducted for the two groups of people to collect relevant data. Tears are collected by capillary glass tube and stored for further Raman analysis.

Inclusion Criteria:

• People aged 20-35 who use eyeliner or do not use eyeliner .
• People who use eyeliner have used it for ≥ 1 year; Frequency ≥ 3 times/week.

Exclusion Criteria:

• Other serious systemic diseases.
• Other systemic diseases related to ocular surface, such as rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome and other immune system diseases or other eye diseases, history of eye surgery and trauma.
• Lactating women or pregnant women.
• Use electronic products for more than 4 hours every day.
• Patients with circadian rhythm disorder.
• People with radiation exposure history.
• Non permanent residents in Wuhan.

The main population of our study is the young women who do not have other diseases that affect the health of eye surface and use or do not use eyeliner.