Contact Lens & Anterior Eye 36 (2013) 4–12 Contents lists available at SciVerse ScienceDirect Contact Lens & Anterior Eye j ourna l ho me p ag e: ww w.elsevier.com/locate/clae Review Daily disposable lenses: The better alternative P. Cho * , M.V. Boost The Hong Kong Polytechnic University, Hong Kong a r t i c l e i n f o Article history: Received 25 May 2012 Received in revised form 14 September 2012 Accepted 2 October 2012 Keywords: Daily disposable contact lenses Benefits Microbial keratitis Cytotoxicity Cosmetic contact lenses Review a b s t r a c t As the literature has described the increasing penetration of DDSL into the contact lens market worldwide, this review aimed to describe the development of this modality as a solution to the problems experienced with other types of contact lenses. The advantages of DDSL in comparison to reusable lenses are discussed. The important role of the practitioner in prescribing for and managing patients using this lens type are also examined, in particular with respect to non-compliance. Problems with the use of this lens type and possible solutions are explored and new applications and future development in this field are described. © 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved. 1. Background Since the introduction of the first commercial PMMA lenses in the early 1950s, the market for contact lenses has increased dra- matically. Comfort and safety of contact lenses were increased by improvements in rigid materials, in particular, increased gas per- meability incorporated in rigid gas permeable lenses in the late 1970s [1]. The great increase in patients choosing contact lenses for vision correction occurred with the introduction of the more com- fortable soft (hydrogel) lenses. Soft contact lenses were invented by Wichterle and Lim in 1960 [2] but it was not until 1971 that the first FDA-approved soft contact lenses were launched by Bausch + Lomb (“SofLens”) in the United States [3]. Initially, soft lenses were worn for considerable lengths of time, being replaced only annually or even longer [4]. With recognition of problems asso- ciated with prolonged use of a lens, together with reduced cost, the replacement time steadily reduced becoming biannually, quar- terly, monthly, and biweekly [4–8]. More frequent replacements allow for increased comfort and fewer on-lens deposits. Although, a British optometrist suggested the possibility of disposable soft lenses [9] soon after the introduction of soft contact lenses, it was not until a quarter of a century after the launch of soft lenses that a product which actually incorporated this idea, was introduced. This was possible because a molding technology was available for lenses to be manufactured at minimal cost, thus allowing them to be worn once only before disposal [10]. These daily disposable soft * Corresponding author. E-mail address: pauline.cho@polyu.edu.hk (P. Cho). lenses (DDSL) aimed to overcome many of the problems inherent in the use of reusable soft lenses [11–23]. The care of soft lenses was to some extent similar to that of the earlier rigid format in that they need to be cleaned, rinsed and disinfected in a purpose-designed case [24]. However, with the introduction of DDSL, many of these traditional routines were redundant, making their use attractive to a much wider range of potential users. This brought about enhanced overall convenience and improved comfort due to the wear of a new lens every time. 1.1. Problems with conventional modality One of the major problems with conventional lenses (i.e. annual replacement soft lenses) is the build-up of deposits which are both more difficult to remove from this lens material than the former rigid material and are more likely to build up on the soft lenses [12,18,25–28]. Presence of deposits leads to a whole range of prob- lems making the lens uncomfortable, reducing visual acuity, and increasing the risk for infection (see Fig. 1 – Deposit flow chart) [12,18,27,29–46]. The second problem with conventional lens modality is the need for daily cleaning and disinfection, complemented by weekly enzymatic protein removal [24]. These processes require high compliance to ensure efficient removal of contaminants and microorganisms and, sadly, many patients fail to observe the cor- rect routine [22,46–53]. This is exacerbated by failure on the part of the practitioners to instruct and reinforce users in the proper care of accessories, e.g. lens cases [22,54]. In particular, the need for care of the accessories may not be obvious to the users leading to non- compliance, which has been reported to be most common for lens 1367-0484/$ – see front matter © 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.clae.2012.10.073