This study will enroll 63 eligible subjects (126 eligible eyes, complete at least 108 evaluable eyes) in approximately 6 different medical centers in Taiwan, in order to evaluate the efficacy and safety of ST-1 silicone hydrogel daily disposable soft contact lenses (ST-1 lenses) compared to Miru 1day UpSide. Enrolled subjects will be randomized in a 2:1 test to control ratio at Visit 1. Each site will enroll 8 (intended minimum) to 12 (intended maximum) subjects. In order to eliminate the bias, the Investigators and the evaluators will be masked to the treatment assignment of the randomization code. During the study, the Investigator(s) will examine the ocular health via inquiry, slit lamp biomicroscopy (SLB), visual acuity (VA) test, keratometry, and refractive changes. The Investigator(s) will check ocular health and evaluate the inclusion/exclusion criteria of subjects at screening. After entering the study, subjects will be required to wear the lenses on a daily basis, record daily wearing time on a diary, return to the study site at scheduled visits for evaluations and complete the self-assessment questionnaire at Visit 2 to Visit 7 (1 day, 1 week, 2 weeks, 1 month, 2 months, 3 months).

Inclusion Criteria:

1. With either gender aged between 18 to 40 (inclusive) years old.
2. Diagnosis of myopia in both eyes, each ranging from -0.50D to 6.00D with manifest astigmatism of ≤ 1.00D per eye.
3. Understands and signs an informed consent form (ICF).
4. Willing to adhere to the instructions set forth in this study as well as understand and complete all specified evaluation.
5. Willing and able to refrain from using any other contact lenses other than those provided for the duration of the study.
6. Has experience and capability of wearing soft contact lenses.
7. Be a habitual soft contact lenses wearer in both eyes, defined as wearing lenses for at least 8 hours per day, 5 days per week, for a minimum duration of 30 days.
8. Tear breakup time (TBUT) > 5 seconds in each eye.

Exclusion Criteria:

1. Eyes with abnormality or disease as follows:

   1. Evidence of lid abnormality or infection (e.g., entropion, ectropion, chalazia, and recurrent styes).
   2. Clinically significant slit lamp findings (e.g., infiltrates or other slit lamp findings Level 2 or above: corneal edema, tarsal abnormalities, and conjunctival injection).
   3. Other active ocular disease (e.g., uveitis, corneal epithelial defect, severe dry eye, lacrimal duct defect, glaucoma, cornea [infiltrates], conjunctiva, lids, and intraocular infection or inflammation of an allergic, bacterial, or viral etiology).
   4. History of recurrent corneal erosions.
   5. Aphakia.

2. Ocular or systemic allergies or diseases that may interfere with contact lens wear, occur within 2 weeks prior to the Screening Visit.

3. Use of topical ocular medications, except artificial tear, within 7 days prior to the Screening Visit.

4. History of refractive, ocular, or intraocular surgery.

5. Participation in any clinical trial (with the exception of retrospectives studies) within 30 days prior to the Screening Visit.

6. Have risks in dangerous and significant eye edema, congestions, corneal abrasion or neovascularization when wearing contact lens.

7. Any corneal surface roughness.

8. Unable to achieve best corrected visual acuity (BCVA) of logMAR 0.1 or better in each eye at distance using manifest refraction.

9. Females who are pregnant, breastfeeding or who intend to become pregnant over the course of the study.

10. Current drug or alcohol use or dependence that, in the opinion of the Investigator, would interfere with adherence to study requirement.

11. Allergy to any component in the study product.

12. Subjects who wore monovision, multifocal, toric, or rigid contact lenses within 30 days prior to the Screening Visit.

    Note: Monovision is defined as a vision correction method for treating presbyopia in which the dominant eye is corrected for distance vision and the non-dominant eye is corrected for near vision.

13. Use of systemic medications (e.g., chronic steroid use) that are known to interfere with contact lenses wear at the Investigators discretion within 14 days prior to the Screening Visit.

14. Other conditions not suitable for participating in this study judged by the Investigators.

15. Live in dusty or pharmaceutical environments.

Investigators and evaluators will be masked to the treatment assignment of the randomization code. Each site must have an unmasked staff member who will be responsible for dispensing and collecting the study test and control lenses. The randomization code will be provided to this unmasked staff member at the time of subject randomization.

Although this design involves masking of both investigators and evaluators, the official protocol title refers to the study as "Single-Masked" because the subjects are not masked.