Night Lenses for Hyperopia / Presbyopia
(Presbyopia OK lens)
(nighttime BVOK contact lens)
cover all range vision + *daytime spectacle free
modifiable and less dryness
max at around age 65
BVOK Presbyopia / Hyperopic Night Lenses (Orthokeratology)
(OrthoK, OK-lens, Blended Vision Orthokeratology)
Thank you for your interest in BVOK Night Lenses! Below is a general overview of this non-surgical nighttime vision correction option. For more detailed information, please feel free to contact us at Tel: 21530008.
What’s BVOK Night Lenses?
Presbyopia is a condition that causes your eyes to lose their ability to focus on nearby objects as you get older. It happens when the lens inside your eye becomes less flexible, making it harder to see things up close. BVOK Night Lenses, also known as Blended Vision Orthokeratology (Orthok) lenses, are special contact lenses that can help manage presbyopia. These lenses reshape your cornea while you sleep, so you can see clearly without the need for glasses or contact lenses during the day. They can also be an alternative to traditional daytime contact lenses or surgery. BVOK lenses use a series of specially designed contact lenses to reshape your cornea at night, under the supervision of an optometrist. This can help reduce moderate hyperopia and astigmatism during the day, and can also be helpful for people with dry eyes who need to wear contact lenses. Compared to other types of vision correction, BVOK lenses can also minimize the problem of dry eye.
Aim of Night Lenses / Orthokeratology:
1. *daytime spectacle free
2. correct myopia, hyperopia, astigmatism and presbyopia (effect will gradually wear off after stop use of BVOK, BVOK will not affect future cataract surgery accuracy.)
3. contact lens option for dry eye cases
Night contact lens
*daytime spectacles free
For modern accelerated BVOK, the cornea is molded using a specially built, highly oxygen-permeable contact lens in close eye condition. To ensure optimal results, the orthokeratology process requires a high accuracy of corneal profile assessment to match the nighttime contact lens with the eye. This is done using state-of-the-art corneal topography, a kind of shape and profile scanner. The corneal shape modification and accuracy can be reviewed immediately.
Precision Optics Corneal Topographer
• 32 Rings
• 102,000 Analysed Points
• 9600 Measurement Points
• Composite Mapping Coverage 0.25mm to 14mm
• Extrapolated Data Out to 17mm
• Power Range 10 - 100 Diopters
*spectacle free = freedom
Who are suitable for BVOK night lenses?
- Less than -6.00D of myopia, less than -2.00D of astigmatism and less than +4.00D of hyperopia. (For those with myopia stronger than -6.00D or corneal astigmatism higher than -1.50D, full bespoke specialty orthokeratology lens may be needed.)
- Sports and water sports enthusiastic, e.g. swimming, diving, skiing.
- For those not suitable for LASIK refractive surgery
- For those with dry eye problem associated with soft contact lens
1. *Good vision can usually be maintained throughout the day after lens removal.
2. Recent research has shown the usage of Ortho-K to be effective in slowing myopic progression in children  .
3. Ortho-k can reduce myopia of 5.00D within two weeks. However, individual variation does exist.
5. Complications associated with conventional contact lens wear, such as dryness and irritation from dust can be avoided.
6. Safe alternative to LASIK laser refractive surgery with no wounds and no dry eyes.
7. The Orthok-K effect is reversible and can be stopped anytime. The eyes will soon resume their normal condition thereafter.
1. Ortho-k is NOT a CURE for myopia. The Ortho-K effect will wear off gradually after cease of lens wear.
2. Aftercare consultations are necessary to ensure effectiveness and safety.
3. Some contact lens-related problems, such as solution sensitivity, infection, corneal epithelial trauma or ulceration may occur, though the risk of complication is very dependent on compliance.
Attention! *It's important to know that various factors can affect your daytime vision quality. You may still need spectacles with low power for certain visual purposes, even when wearing contact lenses. Complications can happen, but you can minimize the chances of these by maintaining good communication with your optometrist, strictly complying with their instructions, and scheduling regular aftercare consultations. Trust that your optometrist is there to help you achieve the best vision possible while prioritizing your eye health.
1. Cho P, Cheung SW. Protective Role of Orthokeratology in Reducing Risk of Rapid Axial Elongation: A Reanalysis of Data From the ROMIO and TO-SEE Studies. Invest Ophthalmol Vis Sci 2017;58(3):1411-1416.
**Case Example 1.:
- May had myopia -4.00 and reading power +1.75 for her eyes. Since age 48, she slept with BVOK lenses very night. She can function happily in office for computer work without spectacles. She residual prescription was RE+0.50 / LE-0.75.
**Case Example 2.:
- Penny is a water sport enthusiastic. He had myopia -6.00 binocularly. Since age 30, he slept with OK lenses every night. After removal of contact lenses, his vision was around +0.50 to +0.75. He had no need of spectacles for daylife activities.
- After ten years, he experienced reading difficulty. After readjustment of the OK lenses, his residual prescription was RE+0.75 / LE-0.50. He can enjoy his life happily without use of spectacles again.
**Case Example 3.:
- June had myopia -5.00 and presbyopia (reading problem) +2.00. since 50 years old, she cannot tolerate soft contact lenses because of severe dryness.
- By use of night lenses (orthokeratology lenses), she can manage her driving and reading tasks without spectacles. Her residual prescription was usually +0.25 to +0.50 for right eye and -0.75 for left eye.
- She was very happy without need of reading glasses.
**To comply with privacy regulation, the aforementioned case information was modified.
Our Centre provides eye test for Adults and children from two and half years old. The eye test covers refractive errors, visual functions and eye health assessment.
Progressive spectacle lenses + Multifocal contact lenses
We are well experienced in progressive spectacle lenses and multifocal contact lenses fitting for management of presbyopia.
Myopia control & Orthokeratology
our centre also provide myopic control and orthokeratology service to kids and teenagers on indication.
Specialty contact lens services
In our center, we fit specialty contact lenses, such as rigid gas permeable (RGP) lenses, hybrid lenses and scleral lenses.
Health Care Voucher
Our optometrists are appointed Health Care Service Providers of Health Care Voucher Scheme. Eligible Elderly may use Health Care Voucher for payment of eye examination and eyeglasses fee. For more information, you may contact us by telephone number 21530008 for eye examination booking.
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