The tangent streak bifocal contact lens: A clinical evaluation

As the general population grows older, the number of contact lens wearers becoming presbyopic is increasing. For many of these patients, bifocal contact lenses are a welcomed alternative to spectacle wear. The Tangent Streak Bifocal is a recent entry into the field of bifocal contact lenses, and is especially suited to patients who are former rigid lens wearers, and those who demand crisp optics at near and far distances. This clinical evaluation of ten subjects explored patient characteristics which allow the Tangent Streak Bifocal to best perform as it was designed, and also attempted to determine whether simple changes in lens parameters might affect lens performance in specific instances

Electronic systems of knowledge in the world of virtual microscopy

Across a broad range of medical disciplines, learning how to use an optical or light microscope has been a mandatory inclusion in the undergraduate curriculum. The development of virtual microscopy (VM) technology during the past 10 years has called into question the use of the optical microscope in educational contexts. VM allows slide specimens to be digitized, which, in turn, allows the computer to mimic the workings of the light microscope. This move from analog technology (the light microscope) to digital technology (the computer as microscope) is part of the many significant changes going on in education, a singular manifestation of the broader move from print-literate traditions of knowledge (requiring literacy) to an electronics-literate, or "electrate," mode (requiring "electracy"). VM is here used as an exemplar of this broad transition from literacy to electracy, some components of which include data deluge, a multimodal structure, and modularity. Understandably, this transition is important to clarify educationally, especially in a global context mediated via digital means. A related aspect of these educational changes is the move from teacher-directed learning to student-centered learning, or "user-led education," which points to a redefinition of "pedagogy" as "andragogy." The dissemination of the specific value of VM, then, is critical to both learners and teachers and to a more coherent understanding of electracy. A practical consequence of this clarity might be a better application of this knowledge in the evolving fields of computer simulation and telemedicine, areas in which today's medical students will need future expertise