Complete Guide
High Astigmatism, or Soft Lenses You Can't Keep In?
The Complete Guide to RGP Contact Lenses
What RGP is, how it differs from soft lenses, and why it is an entirely different thing from the orthokeratology (Ortho-K) people so often confuse it with — this page explains rigid gas permeable contact lenses, who they might suit, the fitting process, and the safety notes, all at once. Written by Optometrist YoYo, based on clinical fitting practice.
- ✦RGP means a rigid gas permeable contact lens — it holds its shape and has high oxygen permeability, so for people with high astigmatism or a less regular cornea the visual quality is usually more stable and clear.
- ✦RGP is not orthokeratology (Ortho-K): RGP is worn during the day to correct your current vision; Ortho-K is worn at night and reshapes the cornea, a different category of medical procedure. What Beyond Visual provides is daily-wear RGP, not orthokeratology.
- ✦Groups commonly suggested for assessment: high astigmatism (around 2.00D / 200 degrees or above, still subject to individual assessment), an irregular corneal shape, and those who find soft lenses dry and uncomfortable. Whether it suits you must be confirmed by corneal topography measurement and an in-person trial fitting.
- ✦Contact lenses are a medical device: under Article 12 of Taiwan’s Optometrists Act, fitting for those aged fifteen and under must be under the guidance of an ophthalmologist, and no fitting is provided for children under six; any corneal abnormality found during fitting is always referred to an ophthalmologist.
RGP: a rigid, oxygen-permeable lens that holds its ground
RGP is short for Rigid Gas Permeable — a rigid, oxygen-permeable contact lens. Compared with the soft lenses everyone knows, it is harder and smaller in diameter, covering only the central corneal area, and the material has good oxygen permeability.
Its most important property is that it holds its shape. A soft lens drapes onto the cornea and follows every irregular contour; an RGP lens keeps its own shape, and a layer of tear film forms between lens and cornea when worn. For people with high astigmatism, or a less regular corneal shape, that tear layer plus the lens's own stable optical surface can often deliver more stable, clearer visual quality.
Of course, a rigid material also means a more noticeable foreign-body sensation early on and a longer adaptation period. It is not "the more premium contact lens" — it is "one option that may be more appropriate in certain situations." Whether it is your cup of tea only becomes clear after an assessment.
Don't mix them up: RGP, soft lenses, and orthokeratology are three different things
Many people hear "rigid contact lens" and assume it means orthokeratology (Ortho-K), but the two are very different. Sort out where each one sits first, then talk about whether it suits you.
| Type | How It Is Worn | Purpose | Offered at Beyond Visual? |
|---|---|---|---|
| RGP rigid contact lens (daily wear) | Worn during the day, removed at night | Corrects your current vision; holds its shape, so visual quality is stable | ✅ Daily-wear RGP fitting offered |
| Soft contact lens | Worn during the day, removed at night (daily, monthly, etc.) | Corrects your current vision; comfortable early on, quick to adapt to | ✅ Fitting offered |
| Orthokeratology (Ortho-K) | Worn overnight during sleep | Reshapes the cornea through applied pressure; a medical procedure | ❌ Not offered |
Remember one sentence: the RGP on this page is the daily-wear rigid lens that is "worn during the day to correct your current vision," and that is a different matter from orthokeratology (Ortho-K), which is "worn at night to reshape the cornea." This is standard RGP fitting, not orthokeratology (Ortho-K).
Who might be suitable for considering RGP?
Below are the groups clinically suggested most often for an assessment. But please remember: might be suitable is not the same as definitely suitable — it always has to be confirmed by in-person measurement and a trial fitting.
High astigmatism
Generally around 2.00D (200 degrees) of astigmatism or above, where visual quality still isn’t stable enough after soft lens or spectacle correction (still subject to individual assessment)
A less regular corneal shape
People whose corneal curvature or shape is more unusual, and who need a shape-stable lens to provide a stable optical surface
Wanting stable, clear visual quality
Those with high demands on visual stability, willing to invest in a longer adaptation period in exchange for visual quality
Dryness and discomfort in soft lenses
People who get dry and tired easily during long hours in soft lenses and want to assess other options
RGP has a longer adaptation period than soft lenses and needs fuller wearer education and follow-up checks. Whether you are willing to keep up with that care routine is part of assessing whether it suits you — that isn’t a drawback, it is simply the care a rigid lens has always required.
An RGP fitting is a highly individualized process
RGP is not a ready-made lens you put on and walk out with — it is fine-tuned into place step by step from your corneal data. The full process covers the following steps.
Corneal topography measurement
Understanding corneal curvature and shape as the basis for the lens fitting curve
Refractive and visual quality assessment
Confirming the prescription (especially astigmatism) and your visual quality needs after correction
Lens parameter planning
Planning individualized parameters such as lens curvature and size from the corneal data
Trial fitting and fit confirmation
Actually wearing the lens to confirm its position on the cornea, its movement, and how it feels
Wearing and cleaning education
Teaching you the correct insertion, removal, and cleaning routine, extending wearing time gradually through the adaptation period
Regular follow-up checks
Returning to the store to confirm lens fit and wearing comfort, fine-tuning parameters when needed
Because it needs ample measurement and trial-fitting time, we suggest booking ahead rather than squeezing it into a rushed slot.
Safety and regulations: what belongs with a physician goes to a physician
Contact lenses are a medical device, and every contact lens requires correct wearing hygiene and regular follow-up to reduce risk. Please keep these points in mind:
Age limits (Article 12 of the Optometrists Act)
Contact lens refraction for those aged fifteen and under (inclusive) shall be carried out under the guidance of an ophthalmologist; no fitting is provided for children under six years of age.
Abnormalities are always referred to ophthalmology
If abnormal corneal or refractive data is found during the fitting process (for example, a suspicion of keratoconus), the case is always referred to an ophthalmologist for diagnosis, not handled on the optometry side.
Wearing hygiene and follow-up checks
Correct cleaning, not exceeding the wearing schedule, and returning for follow-up checks as arranged are the keys to reducing the risk of infection and complications — a well-fitted lens still needs to be well cared for.
Stop wearing and seek care if uncomfortable
If redness, pain, light sensitivity, or blurred vision occurs while wearing the lenses, stop wearing them immediately and seek medical care — do not push through it.
Read more: articles on related topics
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Frequently Asked Questions
Q: What is an RGP contact lens, and how does it differ from an ordinary soft lens?
RGP stands for Rigid Gas Permeable — a rigid, oxygen-permeable contact lens. It is harder and smaller in diameter than a soft lens, covering only the central corneal area, and the material has high oxygen permeability. The biggest difference from soft lenses is this: an RGP lens holds its shape, and a layer of tear film forms between the lens and the cornea when worn, so for people with high astigmatism or an irregularly shaped cornea the visual quality is usually more stable and clear. Soft lenses, on the other hand, win on early comfort and quick adaptation. Neither is absolutely better; who each suits depends on corneal condition, refractive status, and lifestyle, and requires an in-person assessment by optometry personnel.
Q: Is RGP the same thing as orthokeratology (Ortho-K)?
No — this is the point most often confused. The RGP discussed on this page is a daily-wear ordinary rigid contact lens: worn during the day to correct your current vision, and removed at night. Orthokeratology (commonly called Ortho-K) is worn overnight and reshapes the cornea through applied pressure; it is a different category of medical procedure. What Beyond Visual Optometry provides is standard daily-wear RGP fitting, not orthokeratology. The two differ in purpose, wearing schedule, and who they apply to — do not treat them as the same thing.
Q: Who might be suitable for considering RGP?
Situations in which an RGP assessment is commonly suggested include: high astigmatism (generally around 2.00D / 200 degrees or above, though this still depends on individual assessment), a less regular corneal shape, wanting stable and clear visual quality, or dryness and discomfort after wearing soft lenses. But "might be suitable" is not the same as "definitely suitable" — the final answer depends on corneal topography, tear film status, prescription, and daily routine, assessed in person by optometry personnel and confirmed through a trial fitting. Nothing decided without measurement counts.
Q: Does RGP need an adaptation period? Will it feel like something is in my eye at first?
Yes. Because RGP is a rigid material, early wear usually brings a noticeable foreign-body sensation, and wearing time needs to be extended gradually so the eyes can adapt; this adaptation period is longer than with soft lenses. That is exactly why RGP needs thorough wearer education and regular follow-up checks — covering the correct insertion, removal, and cleaning routine, along with return visits to confirm lens fit and wearing comfort. Whether you are willing to keep up with that adaptation and care routine is itself part of assessing whether RGP suits you.
Q: What steps does the RGP fitting process involve?
A complete RGP fitting usually includes: corneal topography measurement (to understand corneal curvature and shape), refractive and visual quality assessment, planning the lens parameters from the corneal data, an in-person trial fitting and fit confirmation, wearing and cleaning education, and ongoing regular follow-up checks. RGP is a highly individualized fitting in which parameters are fine-tuned into place step by step — not a ready-made lens you put on and walk out with — so it needs a generous allowance of assessment and trial-fitting time.
Q: Is wearing RGP safe? What should I watch out for?
Contact lenses are a medical device, and every contact lens requires correct wearing hygiene and regular follow-up to reduce risk. Under Article 12 of Taiwan’s Optometrists Act, contact lens fitting for those aged fifteen and under must be carried out under the guidance of an ophthalmologist, and no fitting is provided for children under six. In addition, if the fitting process reveals abnormal corneal or refractive data (for example, a suspicion of keratoconus), the case is always referred to an ophthalmologist for diagnosis rather than handled on the optometry side — leaving to the physician what belongs with the physician is our principle.
Q: RGP, spectacles, or soft contact lenses — which should I choose?
There is no standard answer; it depends on your corneal condition, your prescription (especially astigmatism), your visual situations, and your daily habits. Some people wear RGP at work during the day for stable vision and switch to spectacles after hours to rest their eyes; others have low astigmatism and are perfectly comfortable in soft lenses or spectacles. Rather than asking "which is best," have a full assessment done and lay your actual needs on the table for discussion — which is exactly the point of our lifestyle vision analysis: first understand how you use your eyes, then pick the option that genuinely fits.
Q: Where in Xinzhuang or Banqiao can I get an RGP fitting?
Beyond Visual Optometry’s Xinzhuang store (BiYang Optometry Clinic, No. 419-1, Zhongzheng Rd., Xinzhuang Dist., New Taipei City, 02-2206-6700) and Banqiao store (02-2253-1246) both provide ordinary rigid gas permeable (RGP) contact lens fitting, including corneal topography measurement, individualized parameter ordering, in-person trial fitting, and regular follow-up checks. This is standard daily-wear RGP fitting, not orthokeratology (Ortho-K). We suggest booking ahead so there is ample time for assessment and trial fitting.
High astigmatism, or soft lenses you can't keep in? Come in for an assessment
Book a full vision analysis and RGP fit assessment, and our optometry personnel will discuss with you whether it suits your corneal condition and the way you use your eyes. This is daily-wear RGP fitting, not orthokeratology. Xinzhuang 02-2206-6700 (No. 419-1, Zhongzheng Rd., Xinzhuang Dist.), Banqiao 02-2253-1246.
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