Custom Gas Permeable Lenses
What Are Custom Gas Permeable Lenses?
Gas permeable lenses are made from firm, durable plastics that hold their shape on your eye. Modern GP materials allow oxygen to pass through to your cornea, although oxygen transmission depends on both the lens material and thickness. Some silicone hydrogel soft lenses also offer high oxygen permeability, so your eye doctor will select the best lens type based on your individual needs.
Soft lenses drape over your cornea and conform to its shape, while GP lenses maintain their form and create a smooth optical surface. This difference means GP lenses can correct astigmatism and irregular corneas that soft lenses cannot address as well.
Every eye has a unique shape, curve, and size. Custom fitting ensures your GP lenses match these individual characteristics precisely. A proper fit allows the lens to move slightly with each blink, which keeps your eye healthy and comfortable.
- Poor fitting can cause corneal damage or vision problems
- Custom lenses align with your specific corneal topography
- Precise measurements prevent lens edge irritation
- Individual design optimizes tear flow under the lens
We may recommend custom GP lenses for several eye conditions that require specialized correction. Keratoconus, a progressive condition where the cornea becomes cone-shaped, often responds very well to custom GP lenses. People with high astigmatism or irregular corneas from injury or surgery also benefit from these lenses. In some keratoconus cases, a piggyback system that combines a soft lens base with a GP lens on top may be considered for added comfort.
Other conditions include post-refractive surgery corneas and corneal scarring. While corneal GP lenses can be challenging for patients with significant aqueous deficiency or severe dry eye, scleral GP lenses may be considered in select dry eye cases under close supervision. Some patients simply prefer the crisper vision and durability that GP lenses provide.
Good candidates typically need sharper vision than soft lenses can provide or have corneal irregularities. You should be willing to go through an adaptation period, as GP lenses take longer to feel comfortable than soft lenses. Commitment to proper cleaning and handling is also important.
- Patients seeking maximum visual clarity
- Those with corneal conditions requiring rigid lens support
- People who can follow detailed care instructions
- Individuals willing to adapt over several weeks
The Custom Fitting Process
We begin by using advanced instruments to measure the curves and contours of your cornea. A corneal topographer creates a detailed color-coded map showing every hill and valley on your eye surface. These measurements are far more precise than standard vision tests.
We also measure your pupil size and your horizontal visible iris diameter as distinct parameters, along with evaluating how your eyelids interact with your eye. All this information helps us design lenses that fit your specific anatomy perfectly.
Based on your measurements, we select diagnostic trial lenses from our fitting set. You wear these trial lenses in the office while we observe how they move, center, and interact with your tears. We check the fit using special instruments and dyes that highlight the relationship between lens and cornea.
- We evaluate lens movement with each blink
- Fluorescein dye shows the tear layer pattern
- We assess centering and edge alignment
- Your initial comfort feedback guides adjustments
After the initial evaluation, we may modify the lens design to improve fit and comfort. We might adjust the base curve, overall diameter, edge design, or optical zone. Small changes in these parameters can make a significant difference in how the lens performs.
Once we finalize your prescription and fitting measurements, we order your custom lenses from the laboratory. The lab crafts each lens to our exact specifications based on your unique eye characteristics.
The entire fitting process usually requires two to four office visits spread over several weeks. Your first visit includes all measurements and trial lens fitting. We typically see you again after you receive your custom lenses to verify the fit.
Additional follow-up visits may be needed to fine-tune the fit or address any comfort issues. Complex prescriptions or unusual corneal shapes may require more visits to achieve the ideal lens design.
Adjusting to Your New GP Lenses
You will notice your new GP lenses immediately because they feel quite different from soft lenses or no lenses at all. Most people experience a foreign body sensation and increased tearing for the first several days. Your eyes need time to adapt to the lens edges and the firmer material.
Vision may fluctuate during the adaptation period as your tear film stabilizes and your eyes get used to the new optical system. This can be normal early on, but persistent or worsening blur should be evaluated.
Normal adaptation discomfort feels like awareness of the lens, mild irritation, or slight scratchiness that improves as you wear the lenses. Your eyes may water more than usual, and you might experience some light sensitivity. These symptoms should gradually decrease each day.
- Warning signs include sharp or stabbing pain
- Vision that becomes blurry and stays blurry
- Intense redness that worsens over time
- Discharge or excessive mucus production
- Sudden sensitivity to light that does not improve
- Pain or irritation after water exposure while wearing lenses
- A white spot or cloudy area on the cornea
- Rapidly worsening symptoms or inability to keep the eye open
We recommend starting with just a few hours on the first day and adding an hour or two each day. This gradual approach helps your eyes adapt without becoming overly fatigued. You might wear your lenses for four hours the first day, six hours the second day, and so on.
Most patients reach full-day wear within two to three weeks. Rushing this process can lead to discomfort and make adaptation harder, so patience is important during this phase.
Most people notice significant comfort improvement by the end of the second week. By week three or four, many patients report much less lens awareness. Vision typically stabilizes within the first week as your tear film adjusts to the new lens surface.
Some individuals adapt more quickly while others need a full month or more. Age, corneal sensitivity, and previous contact lens experience all affect how quickly you adjust to GP lenses.
Daily Care and Handling of GP Lenses
To insert your GP lens, wash and dry your hands thoroughly. Place the lens on the tip of your index finger and check that the lens is clean, not chipped, and holds its shape. Apply a recommended wetting or conditioning drop if prescribed. Hold your upper eyelid with one hand and your lower lid with the other, then gently place the lens on your eye. The lens should center itself once you release your lids and blink.
For removal, look straight ahead and pull your outer eyelid corner tight toward your ear. Blink firmly, and the lens should pop out onto your cheek or into your hand. Alternatively, you can use a small suction tool designed specifically for GP lens removal.
- Always wash and dry your hands before handling lenses
- Use only recommended wetting or conditioning drops if applicable
- Avoid soaps or lotions that leave residue on your fingers
- If the lens is uncomfortable immediately after insertion, remove it, rinse or clean it, and reinsert
Clean your lenses every time you remove them using an approved GP lens cleaning solution. Place the lens in your palm, apply several drops of cleaner, and gently rub with your fingertip for about 20 seconds on each side. Rinse thoroughly with the appropriate rinsing solution, typically sterile saline, before storing or reinserting. Your GP lens system may include separate solutions for cleaning, rinsing, and conditioning or disinfecting, so follow your prescribed regimen carefully.
- Never use tap water on your lenses
- Use only solutions approved for GP lenses
- Rub gently to avoid scratching the lens surface
- Replace cleaning solutions according to package directions
- Never use saliva to wet or clean your lenses
- If using a hydrogen peroxide system, ensure full neutralization before insertion
- Avoid all water contact with lenses and case
- Use only rewetting drops that are compatible with GP lenses if recommended
Store your lenses in a clean case filled with fresh disinfecting solution every night. The solution both disinfects and conditions your lenses for comfortable wear the next day. Always use fresh solution and never top off old solution in your case.
After inserting your lenses each morning, empty the case, rinse it with disinfecting solution, wipe it with a clean tissue, and allow it to air dry with the caps off. Replace your lens case every month to every three months to prevent bacterial buildup.
GP lenses typically last one to three years with proper care, much longer than soft lenses. However, the exact lifespan depends on how well you care for them and whether they develop deposits, scratches, or warping. We will monitor your lenses at each checkup and let you know when replacement is needed.
Even if your lenses look fine, the material can change over time and affect oxygen flow or deposit resistance. Regular replacement ensures your eyes stay healthy and your vision remains optimal.
Risks, Alternatives, and When Not to Wear GP Lenses
Like all contact lenses, custom GP lenses carry some risks, especially if not used or cared for properly. Understanding these risks helps you recognize problems early and seek prompt care when needed.
- Microbial keratitis or eye infections that can threaten vision
- Corneal abrasions or erosions from lens defects or poor fit
- Corneal infiltrative events and contact lens-induced acute red eye
- Giant papillary conjunctivitis from chronic lens wear or deposits
- Corneal edema or swelling from inadequate oxygen or overwear
- Corneal neovascularization or blood vessel growth into the cornea
- Allergic or toxic reactions to contact lens solutions
Custom corneal GP lenses are one of several options for vision correction, and they may not be right for everyone. Your eye doctor will discuss which approach best fits your eyes, lifestyle, and visual goals.
- Custom soft toric lenses for astigmatism
- Scleral GP lenses that vault over the cornea and rest on the white part of the eye
- Hybrid lenses with a rigid center and soft skirt
- Piggyback lens systems combining soft and GP lenses
- Eyeglasses for all or part-time wear
- In select cases, corneal procedures or refractive surgery when clinically appropriate
There are times when you should not wear your contact lenses to protect your eye health. Remove your lenses and contact us if any of these situations apply.
- You have active eye redness, pain, or irritation
- You notice discharge, especially yellow or green
- Your vision suddenly decreases or becomes blurry
- You have signs of an eye infection or illness with fever
- Our eye doctor has advised you to discontinue wear
Follow-Up Visits and Ongoing Lens Care
We recommend comprehensive eye exams every six to twelve months for GP lens wearers. During these visits, we check your vision, evaluate lens fit, and examine your cornea for any signs of stress or complications. We also verify that your prescription has not changed.
New fits typically require early follow-up shortly after dispensing and again after wearing time increases, especially for keratoconus or irregular corneas. These regular checkups catch small problems before they become serious, and we can adjust your lens parameters if your corneal shape changes or if your wearing comfort decreases.
You may need new lenses if you notice decreased wearing comfort, vision that is not as sharp as before, or increased awareness of the lens edges. Lenses can warp slightly over time, especially if exposed to heat or improper cleaning techniques.
- Persistent blur that cleaning does not fix
- Increased lens awareness after months of comfort
- Difficulty keeping lenses centered on your eye
- More frequent protein or lipid deposits
Protein and lipid deposits can build up on GP lenses despite good cleaning habits. We may recommend enzymatic cleaners or professional polishing to remove stubborn deposits. Some deposits indicate that your lens material needs to be changed to a different formulation.
Scratches cannot be repaired and require lens replacement because they can harbor bacteria and irritate your cornea. Chips or cracks also mean immediate replacement is necessary for your safety and comfort.
Contact our office right away if you develop sudden vision loss, severe eye pain, or intense redness. Eye discharge, especially if yellow or green, needs prompt evaluation. Light sensitivity that makes it hard to be in normal lighting is another urgent concern.
If you suspect an eye infection or corneal abrasion, remove your lenses immediately and call us. These conditions require same-day or next-day evaluation to prevent serious complications. If you cannot reach us promptly or symptoms are severe, seek urgent eye care or emergency evaluation the same day. Never ignore persistent discomfort or assume it will resolve on its own.
Frequently Asked Questions
Custom GP lenses generally cost more upfront than soft lenses because of the extensive fitting process and individualized manufacturing. However, because they last one to three years instead of being replaced monthly or biweekly, the long-term cost may actually be lower. The fitting process also requires more professional time, which adds to the initial investment.
Yes, you can absolutely alternate between your GP lenses and glasses based on your daily activities and comfort. Many patients wear their GP lenses during the day and switch to glasses in the evening. Just be aware that if you stop wearing your GP lenses for an extended period, you may need to go through a brief re-adaptation when you start wearing them again.
Insurance coverage varies widely depending on your specific plan and medical necessity. Many vision plans offer some coverage for contact lenses, though custom GP lenses may require higher copays. If your GP lenses are medically necessary for conditions like keratoconus, medical insurance may provide coverage rather than vision insurance. We can help you verify your benefits before beginning the fitting process.
Most standard GP lenses are designed for daily wear and should be removed before sleep. However, certain GP lens materials approved for overnight wear may be prescribed for specific therapeutic purposes or extended wear schedules. Never sleep in your lenses unless our eye doctor specifically prescribes overnight wear and monitors you closely for safety.
If you lose a lens, contact our office to order a replacement using your existing specifications on file. Because your lenses are custom made, we can reorder the exact same design without repeating the entire fitting process. We recommend ordering a single replacement lens rather than waiting, since wearing only one lens can cause vision imbalance and is not recommended for extended periods.
Getting Help for Custom Gas Permeable Lenses
Our eye doctor is here to guide you through every step of your custom GP lens journey, from initial fitting to ongoing care. We monitor your eye health closely and adjust your lenses as needed to ensure optimal vision and comfort. If you experience any concerns with your lenses or have questions about your care routine, please reach out to us promptly so we can address them together.