History of contact lenses through out the year

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on the transformation of contact lenses across the year

1. TRANSFORMATION OF CONTACT LENSES ACROSS THE YEARS Presented by SUMAN DHAURIA Reg No- AU/2023/0010563 Roll- PG/06/MPHARMP/2023/012 M.Pharm (Pharmaceutics) School of Health and Medical Sciences Adamas University 1

2. Introduction History Classification based on their composition Polymer used in Contact lenses Properties of contact lenses material Contact lenses manufacture Applications Some FDA approved contact lenses and their manufacturer Conclusion References CONTENTS 2

3. A contact lenses are a rtificial visual device used to correct the vision usually placed on the cornea of the eye . ​ Contact lenses remain on the cornea by means of the surface tension of the tear film that is composed by different living and dead cells as c onjunctival , corneal, and keratinized epithelial cells; p olymorphonuclear neutrophils; eosinophils ; lymphocytes and plasma cells. The contact lens floats in the tear film, being a tear layer anterior and posterior to the lens are pulls onto the corneal surface by the tear film on the anterior surface of the lens. ​ Advantage - 1. Cosmetically more pleasant. 2 .​ Lightweight  and virtually invisible   3. Increases field of vision 4. ​No fogging Disadvantage ​ - 1 . Costly 2. Problem for young and old patients 3. Supervision is required 4. ​ Require a lot care INTRODUCTION 3

4. HISTORY FIG 1-Timeline of Contact Lens Evaluation 4

5. CLASSIFICATION Contact lenses can be grouped in three main categories based on their composition: CONTACT LENSES Rigid Contact Lenses Soft Contact Lenses Hybrid Contact Lenses Rigid Contact Lenses- The first rigid lens was made of glass, further replaced by poly methyl methacrylate (PMMA ), was obtained by polymerization of methyl methacrylate (MMA) are used to address astigmatism and corneal irregularities with a variety of designs, including front- toric , back- toric , and bi- toric . Soft Contact Lenses- Soft lenses are made of hydrogels, i.e., water containing polymers, which allow better comfort and higher flexibility than rigid lenses. Soft lens materials may be hydrogels (low- Dk materials) or silicone hydrogels (high- Dk materials ) Hybrid Contact Lenses- Hybrid contact lenses have a central optical zone made of RGP material , surrounded by a peripheral fitting zone made of a silicone hydrogel. 5

6. POLYMER USED IN CONTACT LENSES 6 For rigid lenses ​ Methyl methacrylate ​ 4-methyl-1-pentane ​ Cellulose acetate butyrate(CAB) ​ Silicone rubber ​ Fluoro  methacrylate ​ Itaconate ester ​   For soft lenses Hydroxyethyl methacrylate​ Vinyl alcohol ​ Glyceryl methacrylate​ N –vinyl pyrrolidone ​ For hybrid lenses Silicone acrylate Fluorosilicone acrylate Fluorosilicate acrylic Fluorosilicone acrylate Siloxane acrylate

7. 7 PROPERTIES OF CONTACT LENS MATERIAL ​ Ideal properties for a contact lens material are durability, stability, clarity of vision, and the ability to preserve corneal metabolism by allowing a sufficient oxygen flow to the cornea. ​ Chemical properties - 1.Wettability ,​                                             2.Water content,​                                             3 . oxygen permeability, ​                                            4. Swell factor​ ​ Mechanical properties -   1 .   Comfort, ​                                             2. Visual performance, ​                                             3 . Fitting methods, ​                                              4. Durability ​ Optical Properties - 1. Optical transparency, 2. refractive index, 3. good visual performance.

8. 8 CONTACT LENS   MANUFACTURE FIG 2- Contact lens manufacture .(a) Mass production of soft lenses by Spin casting,(b)Production of individually packaged contact lenses via injection molding process , (c) Contact lens manufacture  by lathe cutting ​.

9. 9 APPLICATIONS Correction of refractive errors, prosthetics, and therapeutics. as sensing platforms and as vehicles for drug delivery. theranostic devices. used as smart platforms in personalized medicine. as color vision deficiency for presbyopia correction . integrating sensors within contact lenses has a broad range of applications, including continuous health monitoring, wearable displays , and minimally invasive screening methods.

10. 10 Extended wear lenses Manufacturer Application period Material % water content Night and Day Ciba vision 30 days Lotrafilcon A 24 Pure vision Bausch and Lomb 30 days Balafilcon A 36 Oxygen Optix Ciba vision 7 days Lotrafilcon B 33 Acuvue Oasys Jonson and Jonson 7 days Galyfilcon A 36 Biofinity Cooper vision 7 days Comfilcon A 48 Table 1: Some FDA approved Contact Lenses and their manufacturers

11. 11 CONCLUSION ​ Contact lenses are a well Established , yet a constantly expanding technology . The global contact lens market in 2018 amounted to over 8 billion USD.Contact lenses have been targeted as diagnostic wearable platforms with a variety of applications, including pressure sensors, glucose sensors, and drug delivery vehicles. The development of contact lenses is still ongoing based on the new technology, which make the lenses more biocompatible, comfortable, safe and cheaper.

12. 12 1. Agarwal S., Agarwal A., Apple D. J., Buratto L., 2002 Textbook of Ophthalmology. Vol. 1, pp. 205-218,  Jaypee       Brothers Medical Publishers (P) Ltd., New Delhi, India.​ ​ 2 .  Moreddu , R,  Vigolo , D &  Yetisen , AK 2019, 'Contact lens technology: from fundamentals to applications', Advanced Healthcare Materials, vol. 8, no. 15, 1900368.   ​. 3. Singh K, Nair AB, Kumar A, Kumria R. Novel approaches in formulation and drug delivery using contact lenses. Journal of basic and clinical pharmacy. 2011 Mar;2(2):87 . 4. Talu S , Talu M , Giovanzana S, Shah RD. A brief history of contact lenses. Human and Veterinary Medicine. 2011 Jun 1;3(1):33-7. ​ REFERENCES ​

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