Many differences exist between brands of contact lenses which impact lens optics. The optics of the contact lens is determined by several factors including lens material1 and design2. Optics is the way in which the refraction of light is managed to maximize vision for the contact lens wearer3. Contact lenses with aspheric optics may provide enhanced vision for many wearers.

14. CVI data on file, 2022. Verve Online Survey with US ECPs who fit clariti® 1 day or private label version. n=121 (77% strongly agree/agree).

MyDay® daily disposable are designed with the same Aberration Neutralizing System™ to provide optimal vision combined with UV blocking* and incredible comfort all day long. The MyDay® daily disposable is available in sphere, toric, and multifocal options.

The restored Fresnel has operated reliably since 1999. It’s only a little finicky, requiring, as it did in the past, some human care and attention to keep it happy. Every week, the protective storm window panes of the lantern room are checked and cleaned, surfaces dusted, and brass polished. Quarterly, the lens is shut down for a complete mechanical check and a thorough cleaning.

6. Patel, N, Edmonson, L, Edmonson, W. Masking Cylinder with Aspheric Soft Lenses. Contact Lens Spectrum. Published 1, July 2004. Retrieved July 28, 2022 from https://www.clspectrum.com/issues/2004/july-2004/masking-cylinder-with-aspheric-soft-lenses

Fresnel Shader

Research tells us that our lens is one of only three lenses in the United States made by the English firm of Chance Brothers. It is in very good condition and needs little mechanical work. Restoring the Fresnel lens and putting it back into operation preserves a significant piece of our maritime heritage for future generations. It is the heart of the Point Cabrillo Light Station.

Reviving the Fresnel as a modern, automated light was no easy matter. It had to be made as reliable as the DCB (Directional Code Beacon, commonly in airports), which had replaced the Fresnel in 1972. Advanced technical support is provided as needed by the US Coast Guard Aids to Navigation Team. The Point Cabrillo Light House combines 19th century technology with the sophisticated electronics of today, and was nurtured to fruition by the lightkeepers’ finest attributes: a passion for detail, creative problem solving, and copious elbow grease.

Fresnel effect

2. Abass A, Stuart S, Lopes BT, Zhou D, Geraghty B, Wu R, Jones S, Flux I, Stortelder R, Snepvangers A, Leca R, Elsheikh A. Simulated optical performance of soft contact lenses on the eye. PLoS One. 2019 May 14;14(5):e0216484. doi: 10.1371/journal.pone.0216484. PMID: 31086372; PMCID: PMC6516737.

‡ With higher oxygen delivery than hydrogel materials, SiHy materials minimize or eliminate hypoxia-related complications during daily wear.

5. Read SA, Vincent SJ, Collins MJ. The visual and functional impacts of astigmatism and its clinical management. Ophthalmic Physiol Opt. 2014 May;34(3):267-94. doi: 10.1111/opo.12128. Epub 2014 Mar 18. PMID: 24635572.

Avaira Vitality™ lenses are highly breathable, bi-weekly replacement lenses designed with the same Aberration Neutralizing System™ as the Biofinity® family. The technology of a Avaira Vitality™ retains the lens surface moist all day, but also blocks transmission of 90% of UVA and 99% of UVB light*.

3. Richdale, K, Cox, I, Kollbaum, P, et al.BCLA CLEAR – Contact lens optics. Contact Lens and Anterior Eye. Volume 44, Issue 2, 2021, Pages 220-239,ISSN 1367-0484,https://doi.org/10.1016/j.clae.2021.02.005

Fresnel Blender

7. Bennett, Edward. Bifocal and Multifocal Contact Lenses. Contact Lenses (2019). Retrieved 29 July, 2022 from https://www.sciencedirect.com/science/article/pii/B9780702071683000131

clariti® 1 day contact lenses also offer aspheric optics and provide silicone hydrogel at a comparable price to some hydrogel lenses13†. In addition, clariti® 1 day contact lenses feature high water content (56%), UVA and UVB blocker*, and a low modulus of 0.5 MPa, comparable with other hydrogel lenses. The clariti family also offers sphere, toric and multifocal options and is an ideal entry-level contact lens for new wearers14.

Fresnel equation

9. Kajita M, Muraoka T, Orsborn G. Changes in accommodative micro-fluctuations after wearing contact lenses of different optical designs. Cont Lens Anterior Eye. 2020 Oct;43(5):493-496. doi: 10.1016/j.clae.2020.03.003. Epub 2020 Mar 19. PMID: 32201056.

Biofinity Energys® and MyDay Energys® are designed for digital device users. DigitalBoost™ technology is an innovative single vision aspheric lens design that delivers a +0.3D digital boost, which helps reduce eye tiredness associated with digital eye strain. Study data demonstrates that devices users have a smaller change in accommodative micro-fluctuations (AMF) when wearing this DigitalBoost™ technology, suggesting reduced ciliary muscle stress when reading on a smartphone or other devices at a close distance9.

At the Point Cabrillo Light Station State Historic Park, lightkeeping has made a comeback. Since the return of the Fresnel lens to service in 1999, the volunteer lightkeepers from Coast Guard Auxiliary Flotilla 87 have been trained to perform maintenance on both the lens and lantern room.

Fresnel Light

The order of a Fresnel lighthouse lens reflects its size. First order lenses are the largest. Our lens is a third order lens.

Contact lenses with aspherical optics can be extremely beneficial for subsets of your patients. By recommending a CooperVision® lens, you can be confident you are offering options in support of visual acuity, lens comfort, and eye health ‡.

The phrase lighthouse keeper conjures a romantic image of stalwart men and women braving storms and a solitary life in remote outposts. There are still many lighthouses in operation today, but the transistorized NAVAID panel, automated lamp changers, and other electronic innovations, have made the profession of lightkeeper virtually obsolete. In 1972, our own Fresnel lens was disengaged, and an aero-marine type rotating beacon was mounted on the roof.

4. Mrochen M, Büeler M. Asphärische optiken: physikalische grundlagen [Aspheric optics: physical fundamentals]. Ophthalmologe. 2008 Mar;105(3):224-33. German. doi: 10.1007/s00347-008-1717-z. PMID: 18309494.

Fresnel pronunciation

13. Based on manufacturers published data. clariti 1 day has Dk/t of 86. Compared to Proclear 1 day (Dk/t 28), 1-day Acuvue Moist (Dk/t 25.5), Dailies Aquacomfort Plus (Dk/t 26) and Biotrue ONEday (Dk/t 42).

The Biofinity® family of lenses are monthly replacement lenses designed with aspheric optics and combined with Aquaform® Technology to gives incredible end of day comfort for your patients. Biofinity® is the most prescribed monthly replacement on the market10 and will fit almost every patient with over 240,000 unique prescriptions11,12.

Fresnel diffraction

Fresnel lens

* Warning: UV-absorbing contact lenses are not substitutes for protective UV-absorbing eyewear, such as UV-absorbing goggles or sunglasses, because they do not completely cover the eye and surrounding area. Patients should continue to use UV-absorbing eyewear as directed.

Lens design and the patient’s pupil size are key to multifocal success. The Biofinity Multifocal has a center-distance (D) lens, which transitions through an aspheric intermediate to an outer near zone for the dominant eye. A center-near (N) lens which transitions through an aspheric intermediate to a spherical peripheral distance zone, is placed on the nondominant eye7. When compared with monovision, multifocal contact lens correction provides great vision without compromising depth perception, with continuous adaptation over the first 15 days of wear8.

8. Fernandes PR, Neves HI, Lopes-Ferreira DP, Jorge JM, González-Meijome JM. Adaptation to multifocal and monovision contact lens correction. Optom Vis Sci. 2013 Mar;90(3):228-35. doi: 10.1097/OPX.0b013e318282951b. PMID: 23376896.

The invention of the Fresnel lens was an enormous technological breakthrough in 1820 that affects us today – for example, in theater lights and car head lamps. These lenses revolutionized lighthouses and saved countless lives. The lighthouse lenses are not in widespread use now and are rapidly disappearing through vandalism and neglect. Not much is known about working on them, which makes the educational aspect of the lens restoration very valuable. We want to record and disseminate this information as thoroughly as possible, to make it possible for others to care for and, hopefully, restore other lenses.

Regular spherical contact lenses have an even curvature across the entire lens surface; in contrast, aspheric lenses have varying curvatures across the surface changing from lens center to lens edge. Aspheric lenses are used to minimize optical aberrations within the human eye4. Parts of the eye including the tear film, cornea, and crystalline lens can induce aberrations. Contact lenses deliberately induce a level of aberration in the lens that is inversely equal to the amount of natural spherical aberration inherent in the eye to help give clear, crisp and sharp vision3.

1. Kollbaum PS, Bradley A, Thibos LN. Comparing the optical properties of soft contact lenses on and off the eye. Optom Vis Sci. 2013 Sep;90(9):924-36. doi: 10.1097/01.opx.0000434275.93435.da. PMID: 23969894; PMCID: PMC3902057.

The CooperVision® portfolio of monthly, bi-weekly, and daily lenses are designed with aspheric optics. The Aberration Neutralizing System™ utilizes aspheric optics to neutralize the aberrations from the eye in the Biofinity®, Avaira Vitality™ and MyDay® families. clariti® 1 day contact lenses also offer an aspheric optical design.