Study to evaluate the safety and efficacy of HI-BRITE large diameter rigid gas permeable contact lens (hexafocon b) test when worn on a daily wear basis in the correction of myopia/hyperopia/astigmatism/presbyopia/ and irregular cornea.

Subjects who meet all eligible requirements for entry into the study will be instructed to insert the Hi-Brite Large Diameter Rigid Gas Permeable contact lens in daily wear basis for clinical evaluation purposes.

Treatment period: 6 months

Inclusion criteria:

• Ametropic or irregular cornea subjects who need to wear spectacle lens or contact lens in their daily life.
• Is of age at least 20 years old and no older than 65 years old capacity to volunteer.
• Has read and signed the Informed Consent Form or waiver. (4) Has myopia or hyperopia -20.00D～+20.00D, astigmatism -0.25~-4.00D, or presbyopia +1.00D～+3.50D.
• Irregular cornea subjects include keratoconus, high astigmatism (>-4.00D) or post-refractive surgery patients.
• No active ocular disease, infection or any disorder of eyelids and conjunctiva.
• Has reasonable expectation of improvement in visual acuity with the test lenses.
• Is willing and able to follow subject instructions and meet the protocol -specified visit schedule. (If subjects missed any visit, they must be discontinued from the study.) (9) Agrees to wear the test lenses at a daily wear basis. (10) Willing to adapt wearing GP contact lens.

Exclusion criteria:

The subject is ineligible for entry into the study if the subject

• Has any systemic disease affecting ocular health.
• Is using any systemic or topical medications that will, in the Investigator's opinion. Affect ocular physiology or lens performance within one (1) week before entering this study.
• Has an active ocular disease or has ever used systemic steroid or any other medicine that may affect significant on vision or healing.
• Has any Grade 2 or greater finding listed in the Quantification of Slit Lamp Observations Form. Subjects with corneal infiltrates, however, of ANY GRADE, are not eligible.
• Has any "Present" finding listed in the Quantification of Slit Lamp Observations that, in the Investigators' judgment, interferes with contact lens wear.
• Has any scar or neovascularization within the central 4mm of the cornea. Subjects with minor peripheral corneal scarring that, in the Investigator's judgment, does not interfere with contact lens wear are eligible for this study.
• Severe dry eye (Schirmer Test<5mm/5min)
• Corneal keratitis
• Is aphakic
• Had undertaken the following surgery: Retina, Glaucoma, Cataract surgery.
• Is amblyopic, BSCVA can't achieve (include) 20/40(0.5) when wear trial lenses.
• Allergy to contact lens solution.
• ls participating in any other clinical research study.
• Pregnancy or Breast-feeding.