Individual Topical Paper : Draft

The Development and Future of Contact Lenses

Executive Summary

The development and proliferation of contact lenses has become increasingly evident in the world today. Its capabilities has far exceeded what it once possessed.

This paper will examine the history of contact lenses since the birth of its idea in the 1500s, specifically why and how it was created. The paper then examines the current state of contact lenses, the developments that have been made as well as the effectiveness in achieving the purpose it was made for. In the process, this paper will analyse the pervasive usage of contact lenses and the divergence from its traditional purpose leading it to where it stands/is today. Finally, this paper would seek to uncover the prospect of contact lenses. The future considerations of where contact lenses is headed and how it would impact the world would be explored. These considerations relate to the following aspects: the functions of future contact lenses, socioeconomic effects and economic effects.

1          Introduction

Since time immemorial, mankind has begun developing technologies in all aspects possible. The creation of fire, tools, weapons and machines were mostly geared towards aiding humankind in what they did or do. Some did venture into the applications of knowledge on the human body.  These were mainly medical aspects which served to overcome diseases or sickness suffered by humans. Many of these technologies served in prolonging the human lifespan, but there were a handful which aimed at enhancing the human condition by correcting defects which developed overtime. One such case was the defect of human vision.

Ametropia or better known as refractive error or in layman terms, image formation defects is a common eye disorder suffered by humans. Refractive error occurs when the eye is unable to clearly focus on the images from the outside world. The result is blurred vision, which is sometimes so severe that it causes visual impairment. The four most common refractive errors are myopia, hyperopia, astigmatism and presbyopia. Myopia (nearsightedness) is the difficulty in seeing distant objects clearly. Hyperopia (farsightedness) is the difficulty in seeing close objects clearly. Astigmatism is the distorted vision resulting from an irregularly curved cornea, which is the clear covering of the eyeball. Lastly, presbyopia leads to difficulty in reading or seeing at arm's length, it is linked to ageing and occurs almost universally. Refractive errors cannot be prevented, but they can be diagnosed and treated with corrective glasses, contact lenses or refractive surgery. WHO estimates that there are still 153 million people worldwide living with visual impairment due to uncorrected refractive errors. This figure does excludes the people living with uncorrected presbyopia, which is expected to be of a significant amount as shown by earlier evidence. (WHO, 2013) A global estimate of 2.3 billion people suffer from poor vision due to refractive error (Thulasiraj, Aravind, Pradhan, 2003).

Eyeglasses and contact lenses are used mainly to correct refractive errors. They have been used to correct the human vision for a long time. Eyeglasses have been invented since 1285AD (Letocha, Dreyfus, 2002). However, it was not until 1508AD that the idea of contact lens was conceived (Efron, 2010). Although the idea of the contact lens was believed to be conceived in 1508, it was 380 years later before contact lenses were actually fabricated and worn by people.

A contact lens is a thin lightweight device that is placed directly onto the cornea of the eye. It is used in for corrective, cosmetic or therapeutic purposes. Contact lenses have various benefits for wearers, such as appearance and practicality. Many people choose to wear contact lenses as opposed to eyeglasses as they do not steam up, they provide a wider field of vision, and they are more suitable for a number of sporting activities (Bedinghaus, 2009). There are generally two categories of contact lens, soft and rigid gas permeable (RGP) contact lens (FDA, 2013). These two categories will be further explored in the later stages. Basically, they differ according to their materials and purposes. As suggested by their names, the soft lens has a softer texture while the RGP contact lens has a harder, more rigid texture.

2          Historical Perspective

Many contact lens historians credited Leonardo da Vinci with describing and sketching the first ideas for contact lenses in 1508. They believed that his book Codex of the Eye, Manual D, written in 1508, introduced the optical principle underlying the contact lens. The underlying principle was the alteration of corneal power. Indeed, Da Vinci did describe a method of directly neutralising corneal power, by submerging the head in a bowl of water (figure 1). However, Da Vinci did not mention of any mechanism or device for correcting vision, instead he was primarily interested in learning about the mechanisms of accommodation of the eye (Heitz and Enoch, 1987, as cited in Efron, 2010).

Years after, a number of others illustrated theories in relation to the underlying principle of directly altering corneal power. In 1636, Rene Descartes described a glass fluid-filled tube which was to be placed in direct contact with the cornea. Though it was aimed at altering corneal power, the theory was impractical as it made blinking impossible (Efron, 2010). Then in 1801, Thomas Young ran a series of experiments, constructing a device similar to the one described by Descartes. He constructed a device that was essentially a fluid-filled eyecup that fitted snugly into the orbital rim (Young, 1801). The device was somewhat more practical in that it could be held in place with a headband and blinking was possible, but the device was created with regards to the mechanisms of accommodation and not for the correction of refractive errors. Later in 1845, Sir John Herschel suggested two possible methods of correcting critical cases of irregular cornea in the 1845 edition of Encyclopedia Metropolitana. The first method was the application of a spherical capsule of glass, filled with animal jelly, to the cornea, while the second method consisted of impressing a mould of the cornea on some transparent medium (Herschel, 1845, as cited in Efron, 2010). Although Herschel did not conduct such experiments, his theories were adopted some 40 years later by inventors unbeknown to each other and who were all apparently unaware of Herschel’s writings (Efron, 2010).

During the late 1880s, there was extensive research on contact lens which led to the debate as to who first successfully fitted the contact lens. It was believed that Adolf Eugene Fick, a German ophthalmologist working in Zurich, was the first to illustrate the process of frabricating and fitting of the contact lens. In 1888, he illustrated the fitting of a focal scleral contacts shells first on rabbits, then on himself and finally on a small group of volunteer patients (Efron and Pearson, 1988). On the other hand, in 1889, August Muller who was a student at Kiel University in Germany, was credited for the fitting of the first powered contact lens. He managed to correct his own high myopia with a powered scleral contact lens (Efron, 2010).

From 1936 to 1974, further developments were made on contact lenses. These developments involved the introduction of new materials of transparent plastic (polymethyl methacrylate: PMMA), and silicone elastomer. Then after lenses were separated into rigid or hard lens and soft lens. At that point of time, PMMA was used to make rigid lens, while silicone elastomer was used for soft lens. Changes in materials were due to limitations of each material, such as impermeability to gases in PMMA and the hydrophobic surface of silicone elastomer. These limitations have to be treated to allow effective and comfortable wear. Eventually, they were solved with the introduction of new materials. Advancement in technologies allowed incorporation of materials and for lenses to be made from new materials. This allowed the previously impermeable to gas nature of PMMA to transform into a permeable to gas nature. Substances such as silicone, styrene and fluorine were incorporated into the rigid material of PMMA for the transformation to occur. For the soft lens, hydrophilic gels, specifically hydroxyethyl methacrylate (HEMA) was introduced as a new substance used to manufacture lens. Its enhanced biocompatibility and comfort, as compared to silicone elastomer, made it a success. During this period,scleral lenses, which rest on parts of the sclera, were also modified into relatively smaller corneal lenses, which covers only the cornea (Efron, 2010).

Nonetheless after the developments made in soft, patients still suffered from severe eye reactions after prolong usage of the same pair of lenses. Lens deterioration over time was a major impediment to successful long term lens wear. Moreover, the high unit cost of lenses made regular lens replacements unfeasible. Subsequently, a group of Danish clinicians and engineers, led by ophthalmologist Michael Bay, developed a moulding process so that low-cost, multiple individual lens packs could be produced (Mertz, 1997, as cited in Efron, 2010). This product was known as Danalens. In 1988, Danalens’s packaging system and moulding technology was further refined and the result was the Acuvue lens. Acuvue lens is an inexpensive replacement extended-wear lens. Still, the concept of contact lenses suffered from hypoxic lens-related problems, which severely limited the clinical utility of contact lenses, especially for extended wear (Efron, 2010).

A decade later, silicone hydrogel lenses were introduced into the market. This was a significant advancement in contact lens material technology, solving the long frustrating problems related to hypoxic lens. Within a decade, all major contact lens manufacturers have adopted the silicone hydrogel material and introduced silicone hydrogel lenses (Efron, 2010).

It can be seen that the developments of contact lens in the past were focused on getting the right material for the manufacture of contact lenses. The materials had to allow high oxygen permeability and be biocompatible with our eyes, providing us comfort and safety. In addition, the main purpose of contact lens was to correct the vision of our eyes by altering corneal power.

3          Current Situation

In the year 2012, the number of people wearing contact lenses worldwide was an estimated 125million. Contact lens wearers had an average age of 31 years old and 67% of wearers were female (NEI, 2012). Interestingly enough the current purposes of contact lens are reflected in these statistics. In the present world today, contact lenses are used for various purposes, not just for the correcting of vision through altering corneal power anymore. This section will explore the other forms of usage of contact lens, its therapeutic purposes and its aesthetic purposes respectively.

3.1       Other Medical Purposes

Besides correcting vision through the alteration of corneal power, currently contact lenses are also used to meet other medical objectives, such as prevention or delay of diseases and providing aid to people suffering from colour blindness. In recent years, researchers have developed UV-blocking contact lens in a bid to reduce UV radiation entering our eyes. One benefit of minimising UV radiation to the eyes is reducing the risk of age-related macular degeneration. Age-related macular degeneration is a major cause of severe vision loss for people over the age of 55. Past research have suggested that maintaining a higher level of macular pigment appears to have a protective effect against age-related macular degeneration. According to a study presented at the 2012 British Contact Lens Association Clinical Conference, UV-blocking contact lens has the ability to maintain the eye’s macular pigment density (Johnson & Johnson Vision Care, Inc., 2012). Hence UV-blocking contact lens could be used to delay age-related macular degeneration. UV radiation could cause many other diseases in eyes as well, the more common ones are photokeratitis – sunburn of the eye, cataracts and cancer in the eyeball (Woerner, 2013). The use of sunglasses have been able to protect the eyes from UV radiation, but UV-blocking contact lens provides additional protection from this radiation. UV-blocking contact lens is able to absorb UV radiation from coming from all angles, including angles not covered by sunglasses. Moreover, these lens would provide all day UV protection, as people would normally wear their contact lens throughout the day as compared to sunglasses which are taken off when they are not needed. Furthermore, scientist from the Institute for Bioengineering and Nanotechnology (IBN) in Singapore have developed contact lenses that darken in response to ultraviolet light. These lenses contain photochromic dyes comprising of particles that change shape under UV light, hence becoming darker which protects the eyes from UV rays (Scott, 2009). With the introduction of UV-blocking contact lenses these eye diseases would be further prevented and delayed in human beings.

Another objective of contact lenses is to aid the colour blind. The X-Chrom lens, a monocular corneal contact lens have been developed to do so. It significantly enhances colour perception for those who suffer from the colour deficiency. For instance, a colour blind person would wear a deep red tinted X-Chrom contact lens in the nondominant eye in order to intensify the colour of red and green (Art Optical Contact Lens, Inc., n.d.). One shortcoming, is that it does not cure the vision problem of colour deficiency, but only facilitates better colour differentiation.

3.2       Therapeutic Purpose

Therapeutic purposes can also be linked to medical usage of contact lenses. Therapeutic usage of contact lens include bandage contact lens and contact lens that deliver drugs to the eye. When people suffer from corneal damage due to eye disease or injury bandage contact lenses are used to promote healing and reduce discomfort. They protect the eye from external assault and also isolate the corneal surface from friction during blinking. Bandage contact lenses are also used after eye surgery, as they allow for easy installation of medication as compared to other protective barriers. Additionally, they act as a reservoir for medications, increasing the amount of time the medication stays in contact with the eye (Trattler, n.d.). Eye drops account for 90 percent of all eye medication, but they are inefficient. Doctors estimate that only up to 7 percent of the eye drop medication is actually absorbed into the eye. The other 93 percent flows out of the eye and drips down the cheeks. More often than not, patients tend to forget or avoid taking their eye drop medications as it is a hassle. Drug-dispensing contact lenses serve to solve these problems. Recently, researchers have created a contact lens that is able to deliver a high concentration of antibiotic at a constant rate for more than 30 days. The drug-dispensing contact lens would not affect the wearer’s vision, because the drug containing portion of the lens is shaped like a doughnut (Figure 2) (Leggett, 2009). With this invention, many eye related medication can be replaced or complemented with it.

3.3       Cosmetic Lenses

The rise of cosmetic contact lenses is becoming increasingly prominent. Nowadays, contact lens wearers tend to purchase tinted contact lenses to beautify themselves. Even people who need not wear contact lens do purchase zero-powered cosmetic contact lenses for aesthetic purposes. Cosmetic lenses can be customised to individualise look or enhance performance. Cosmetic contact lenses are effective in changing eye colour and appearance. They may be used in several therapeutic applications such as masking disfigured eyes (The British Contact Lens Association, n.d.). Other applications involve personal grooming, the movie making industry and professional athletes. In the sports sector, colour tinted lenses are used to increase visual performance. These lenses reduce glare, enhance contrast sensitivity and heighten depth perception. For example, a green tint lens can enable a tennis player to see the ball more clearly on the court (Surtenich, 2013). On another note, an Indian optometrist has went a step further in making contact lens as an accessory. Chandrashekhar Chawan created the world’s first contact lenses embedded with diamonds and gold (Figure 3). The lens is designed in such a way that it would not stop oxygen from getting to the eye and can be customised to correct any visual impairment. It is also said to be comfortable to wear, with the lens being able to hold water in front of the cornea to soothe the eye (Scott, 2011).

3.4       Limitations

Generally, contact lens pose a serious threat to the eyes without proper use and supervision. Contact lenses can cause eye irritations or infections, if not treated in time it could lead to blindness. For example, fungal eye infection is possible with the usage of contact lenses. This condition can lead to blindness and include symptoms like blurry vision, pain or redness, increased sensitivity to light and excessive discharge from the eye (NBC News, 2006). Swimming with contact lens is also a danger. In fact, the United States Food and Drug Administration recommends that contact lenses should not be exposed to any kind of water, including water in swimming pools, showers and tap water (Surtenich, 2012). This is because water could be home to countless of viruses and dangerous microbes, which could potentially infect the eye and cause blindness. In order to minimize chances of such conditions contact lens users should maintain high hygiene standards, follow medical advises and seek regular medical checkups from their eye doctor.

Contact lenses are also not made readily available globally. As the usage of contact lens requires supervision by professionals and certain technologies to do so, less developed countries often have little or minimal availability of contact lenses. Some contact lenses can also be quite costly itself. Even if more affordable contact lenses such as cosmetic lens are made available to less developed countries, professionals and proper eye care material would be needed to educate and facilitate the usage of lenses. Hence, the current distribution of contact lenses is limited to the more affluent societies and less developed societies are unable to utilise this technology.

4          Future Considerations

Projecting into the future, the acceleration in the development of contact lenses could herald an age of revolutionary change. There are immense amount of possibilities with research and innovation being done on an equipment the size of a fingertip. Contact lenses could literally change the vision of the whole world. This section examines the considerations which the author believes might arise in the future if contact lenses were to be further developed and adopted on a massive scale.

4.1       Lenses of the Future

The possibility of having bionic eyes with the ability to zoom in on a distant object and project virtual displays seem surreal. Yet, for the first time a group of engineers at University of Washington have created a biologically safe contact lens with an imprinted electronic circuit and lights. A completed lens was said to have the display superimposed on the outside world. The engineers tested the lenses on rabbits and no adverse effects were shown by the animals (Moskowitz, 2008).

The lens served as a step towards the development of bionic lens in the future, showing that the idea is feasible. If bionic lenses are indeed created in the future, it would yield a plethora of possibilities. The author believes that the successful innovation of this technology in the future would simplify processes by incorporating various purposes into it. People no longer have to carry around communication devices or even a laptop, the functions would be projected on a midair virtual display screen that only the user would be able to view. Of course this would require the combination of several technologies, maybe even some which are not in the market yet. The army could utilise the lenses to simulate training, in turn reducing the resources needed for trainings. Perhaps, drivers could even see their route plotted on the windshield. At that point of time the use of Google Glasses would be irrelevant being superseded by the advantages of lenses. The future could be a time where contact lenses exerts its dominance globally, where owning a pair of lenses becomes a necessity.

Contact lenses of the future might also eliminate or at least significantly reduce the occurrences of many eye diseases. Presently, contact lenses already do so much in the medical field as elaborated earlier in the previous sections. All the more in the future, advance developments would be made and contact lenses could aid those visually impaired, possibly helping them gain some sight. In addition, it could help detect eye diseases early on without the need to visit the doctor. For example, the lenses could be designed to observe eye conditions and identify irregularities, so eye disease like glaucoma which symptoms do not normally appear early on can be detected earlier on and treated before the dire effects takes its toll on the person.

4.2       Socioeconomic Effects

The author believes that another future consideration on the development of contact lens would be the socioeconomic impact on the world. The prices of contact lenses of the future might bring about significant inequality worldwide.

Currently, not all types of lenses are at affordable prices. For example, orthokeratology lens which corrects refractive errors of the eye costs a few hundred dollars per piece. Furthermore, the price of purchasing a technology similar to bionic lenses, the Google Glasses, presently costs US$1,500 per pair. With the use of advanced technologies and intricate manufacturing process, the price of bionic lenses in the future would be considered astronomical by the less affluent. The author submits a scenario that future contact lenses, such as the bionic contact lens, could be made a product which marks or exemplifies the social status of the more affluent. Now, products like apparels and accessories are already being used to symbolise the status of the rich. In the future, contact lens companies could control the price or distribution of bionic lens making it exclusively available only to those who can afford or deserve it. Hence, only the rich and powerful could utilise this particular technology, while the rest would be at a disadvantaged lacking the technology and possibilities it could bring.

On the other hand, overtime with the advancement of technologies, the manufacturing process might be made more efficient and simplified, leading to a reduction in cost. Governments can also implement policies to promote competition in the contact lens industry, which encourages technology advancement and reducing cost at the same time. Therefore, there might come a time when future lenses are made affordable even to the less affluent. This would allow people of all financial status to utilise the available technology.

4.3       Economical Effects

The author believes that with the imminent rise of the functions of the contact lens, the contact lens industry could be expanded and evolved. As of 2012, an estimated of only 125 million out of 7 billion people in the world wear contact lenses (NEI, 2012). If every person in the world wore contact lens the market would be expanded by 56 times. In the future, the market of contact lens is bound to be even large, as the population of the world continues to grow.

In the future, with a substantial increase in functions of contact lenses its use would be made more relevant to the world. The author depicts that if contact lenses do one day replace communication devices, maybe even some electronic devices, the use of contact lens would be necessary for all. The market of contact lenses would be collaborated with all other communication devices and electronic devices, possibly making it one of the biggest industries in the world. In addition, the product could have so many variations that it could evolve into an industry similar to the phone industry. Contact lenses could be classified into different types and models, with companies competing to produce better models into the market. The expansion of the contact lens industry, would create countless of jobs and increase trade globally. With a considerable amount of economic activities originating from contact lenses, it could be one of the drivers of economic progress in countries.

5          Conclusion

This paper has examined the transformation of contact lens overtime. The original concept and purpose of contact lens served as a foundation for this finger-tip sized technology. The advancement in technology has amplified its capabilities and made contact lenses safer to wear. Though there are limitations to the uses of contact lens, many still utilise it and future developments could possibly solve them. The author believes that humankind has only scrapped the surface of potential of contact lenses. With the advancement in technologies and growing concepts, contact lens could one day be a dominant technology of the world.