Contact Lens Design Process

Contact Lenses at CLEI

Dr. John D. Gelles, is the director of the specialty contact lens division of the Cornea and Laser Eye Institute, P.A. in Teaneck, NJ.  He is a Specialty Contact Lens provider and PROSE Clinical Fellow.

Dr. Gelles is a renowned expert in specialty contact lens design, fitting, and management. Patients travel to our institute from all over the world for treatment due to his excellence in and dedication to the field of specialty contact lenses. He has extensive experience with specialty and custom contact lenses for particular indications and creates custom contact lenses unique to you and your needs.

Traditional Contact Lenses vs Specialty and Custom Contact Lenses

Traditional or routine contact lenses are manufactured by the millions each day. They are available in soft material only and are made in a cast molding process, which allows large batches of lenses to be made all at once in a highly automated process. These lenses are made to fit the average normal cornea and eye shape; one size fits most approach. The powers available are again made for the average powers of normal eyes. Individuals who fall outside of the average range typically experience issues with these lenses and benefit from a specialty contact lens.

Specialty contact lenses are custom, tailor-made for an individual’s cornea and eye shape under the doctor’s exact specifications. Thus, it is important to recognize that the skill of your doctor is paramount to your success. These lenses are produced by a lathe cut process, where one lens is manufactured at a time to your individual specifications. These lenses can be made of either soft or rigid materials (or combined) in virtually any shape or size. The only limitations are the lathe’s physical limitations and the extent of your doctor’s skill, experience, and ability to find innovative and imaginative solutions to meet your specific needs.

Specialty Contact Lens Options

Dr. Gelles’ subspecialty expertise in specialty and custom contact lenses include custom scleral lenses, PROSE devices, custom hybrid lenses, custom piggyback lens systems, custom corneal gas permeable (GP) lenses, custom rigid contact lenses, custom RGP lenses, soft contact lenses, custom soft contact lenses for vision improvement in keratoconus and other irregular corneas. As director of the specialty contact lens division of the CLEI Center for Keratoconus, he has the most extensive experience designing custom contact lenses for patients with keratoconus in the nation. As a PROSE clinical fellow, he frequently utilizes PROSE treatments for patients with severe forms of ocular surface disease. His expertise in therapeutic lenses extends to therapeutic scleral lenses and therapeutic soft lenses for severe dry eye disease and ocular surface disease. For those with normal corneas and vision correction needs, his expertise extends to specialty, custom, and standard soft and rigid contact lenses for those with complex prescriptions, those seeking to improve reading vision with a multifocal or bifocal contact lens or previous difficulty with contact lens wear. As a fellow of the International Academy of Orthokeratology and Myopia Control, he is an expert in orthokeratology (ortho-k, CRT, VST) lenses for overnight, glasses and contact lens free, vision improvement, and myopia control as well as MiSight and custom soft lenses to manage myopia. Additionally, he is an expert in custom colored contact lenses (both cosmetic and theatrical) and prosthetic contact lenses for cosmetic and vision enhancement. Dr. Gelles and the CLEI team will perform extensive evaluations to design the best lenses for your needs and maximize your success in contact lenses.

Custom Contact Lens Design and Fitting Process

The Initial Evaluation

At the Cornea and Laser Eye Institute, patients undergo an advanced comprehensive evaluation using sophisticated technologies to optimize results. Using this evaluation, your individual needs can be matched to the proper specialty contact lens to achieve the best outcome. This advanced ocular examination will typically take a couple of hours to complete. Once this baseline information is gathered, the lens design and fitting process can begin.

The Lens Design and Fitting Process

During your initial evaluation, the lens design process will begin. Just like a fingerprint, each eye has its own unique contour. There is even a significant difference in the shape when comparing the 2 eyes of the same individual. Specialty contact lenses are tailored to the anatomy, physiology,  and visual needs of your individual eyes. From the lens materials, physical lens parameters, and optics, the process aims to determine and create lenses to achieve these three goals; improved vision, ample comfort, and optimum health. There are several techniques used in the process to design your lenses.

Diagnostic Set Design

The classic way to fit and design specialty contact lenses is by using a diagnostic contact lens set. A series of lenses with varying curvatures are placed on the eye. The lens’s alignment is evaluated, and during the design process, modifications to the lenses are made based on the observations and eye performance. At the Cornea and Laser Eye Institute, Dr. Gelles has over 100 different diagnostic contact lens sets at his disposal, yielding well over 2,500 unique lens designs. In contrast, the average practitioner may have 1 to 3 diagnostic sets.

Diagnostic contact lens sets for scleral lenses, hybrid lenses, corneal gp lenses, rgp lenses, piggyback lenses, custom soft lenses , and cosmetic contact lenses. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.

Scan Based Design

An additional approach is the use of scan based specialty contact lens design. Using highly specialized devices to scan the ocular shape, this data is used to create a digital model of the eye. At the CLEI Center for Specialty Contact Lenses, Dr. Gelles has access to 4 devices capable of capturing this data, while the average practitioner will not have access to these devices. Once this model is created, Dr. Gelles will use specialized computer aided design software to create a lens unique to the eye’s contour.

Corneal cross-sections from a tomographer, used to create a 3d model to build a custom scleral lens, ortho-k lens, or other specialty contact lens. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.

Impression Based Design

Another approach is the technique of ocular impressions. Using a specialized gel, an impression of the eye is obtained. This impression is then 3D scanned, creating a digital model of the eye. Using this model and highly specialized computer aided design programs, completely bespoke lenses can be created. Dr. Gelles has been a pioneer in this technique. He was the first to perform it in the northeastern United States and is currently the only doctor trained to do so in New Jersey. Less than 0.1% of practitioners in the world are trained on this technique.  

A impression of cornea and ocular surface, this will be 3D scanned and used to create a model of the eye which custom scleral lens, corneal gp lens or other specialty contact lens. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.

Once the initial visit is complete, your individualized specialty contact lenses will be fabricated. The lenses will typically take 1-2 weeks before they arrive in the office for the final verification process before being dispensed.

Derived Specialty Contact Lenses

A custom scleral lens made by a process of diagnostic lens fitting and design. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.

A custom scleral lens made by a scan or impression based design technique. Notice the unique shape of the lens, designed to fit the exact contours of the eye. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.

Both are custom made scleral lenses derived from diagnostic fitting, scan based, or impression based data. Both lenses lead to a successful result. Though the examples above are of scleral lenses, these scan and impression data derived lenses can be applied to other lens types such as custom soft lenses, hybrid lenses, and corneal GP lenses. 

The Lens Dispense and Training Session

Once the lens parameters have been verified, the lenses can be dispensed at the application and removal training session. At this visit, patients are trained on safe methods for contact lens handling, application and removal of the lenses, and cleaning the lenses. Additionally, your prescribed specialty contact lens cleaning solutions routine will be reviewed.

Dr. Gelles will have prescribed specific lens care solutions based on your physiology and lens material properties. It is important only to use the prescribed solutions as other solutions may damage your eyes or lenses. Dr. Gelles may change these solutions at subsequent visits to optimize physiology, comfort, and lens performance. 

Once adequate technique and understanding of lens care have been demonstrated, you can take your new specialty contact lenses home. 

The Lens Follow Up Evaluations

After wearing the lenses daily, a follow-up visit will take place in approximately 1-2 weeks. These visits are aimed at evaluating the performance of the lenses. If the lens design needs to be modified, another set of lenses will be fabricated, verified, and dispensed. Generally, more complex cases require more lens revisions.

The Lens Optics

Toward the end of the lens follow-up evaluations, highly customized optics may be utilized to improve your vision further. These optics may include blended optics to increase near reading capability or optics to correct for astigmatism to improve clarity. For those with irregular corneas or those with extraordinary vision requirements, the addition of wavefront guided higher order aberration correcting optics on scleral lenses can further improve your vision over traditional optics.

Vision Simulation of an Irregular Cornea Condition

Vision Simulation of a Severe Irregular Cornea Condition. Images by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.

An irregular cornea creates blurred vision that can be described as distorted, overlapping, or ghosted and is also responsible for glare, flare, and halos. These visual distortions are called higher order aberrations. Glasses and standard soft are not effective in correcting or improving vision from these aberrations.

Traditional Optics over an Irregular Cornea Condition

Traditional Optics over a Severe Irregular Cornea Condition. Images by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.

When a specialty contact lens is worn over an irregular cornea, the lenses create a smooth refractive surface that masks the corneal surface. Traditional lens optics will typically provide ample clarity to your vision by significantly reducing the higher order aberrations.  Occasionally this improvement may, despite all efforts, be unable to satisfy your visual requirements.

Wavefront Guided Higher Order Aberration Correcting Optics over an Irregular Cornea Condition.

Higher Order Aberration Correcting Optics over a Severe Irregular Cornea Condition. Images by John D. Gelles, O.D. Copyright © 2020 by The CLEI Center for Specialty Contact Lenses. All Rights Reserved.

These optics are considered high definition optics as the clarity is improved over traditional optics. These optics have been studied in university based laboratory settings over the past 10 years. The average improvement is a 50% percent reduction in aberrations and 1 or more lines of visual acuity improvement. These optics are currently limited to application on scleral lenses. At the Cornea and Laser Eye Institute, Dr. Gelles is running a clinical trial to evaluate vision improvements with this technology.

The lens refinement process will repeat until a combination of improved vision, ample comfort, and optimum health is achieved, and the lenses can be finalized. Once a final pair of lenses is achieved, follow up examinations must be scheduled to ensure your ocular health and the condition of your lenses are maintained.

Follow Up Examinations

Follow up visits will be scheduled at the Cornea and Laser Eye Institute to monitor the condition addressed by the contact lenses and the condition of the lenses. Specialty contact lenses will last various lengths of time unique to each individual, based on lens material properties, physical lens condition, the lens to eye fitting relationship, clarity of optics, lens cleaning habits, and ocular physiology.

These follow up examinations may be collaborative, involving a visit with two doctors. In these cases, Dr. Gelles will evaluate the lenses and condition first, then Drs. Greenstein, Hersh, or Chu will further evaluate the underlying condition. In general, more complex or higher risk cases will be followed at shorter intervals.


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