ABSTRACT
In this paper, a low-cost lens fabrication method using a micro chamber produced by a three-dimensional (3-D) printer is presented. The shape of polydimethylsiloxane (PDMS) membrane was controlled by adjusting the pressure inside the chamber. On top of the shaped membrane, an ultraviolet-curable resin was poured. Depending on the pressure inside the chamber and the shape of the chamber lid, three types of lenses could be made: a bi-convex lens, a plano-convex lens, and a concave lens. This method can reduce the cost of making pilot or evaluation devices in healthcare service.
Subject(s)
Smartphone , LensesABSTRACT
In this paper, a low-cost lens fabrication method using a micro chamber produced by a three-dimensional (3-D) printer is presented. The shape of polydimethylsiloxane (PDMS) membrane was controlled by adjusting the pressure inside the chamber. On top of the shaped membrane, an ultraviolet-curable resin was poured. Depending on the pressure inside the chamber and the shape of the chamber lid, three types of lenses could be made: a bi-convex lens, a plano-convex lens, and a concave lens. This method can reduce the cost of making pilot or evaluation devices in healthcare service.
Subject(s)
Lenses , PolymersABSTRACT
PURPOSE: To analyze blinking patterns when watching an ultra-high definition (UHD) television and to compare the results between normal eyes and dry eyes. METHODS: A total of 59 participants aged from 13 to 69 years were instructed to watch a colorful and dynamic video on a UHD television for 10 minutes. Before and after watching the UHD television, we measured the best corrected visual acuities, autorefraction, tear-break-up-time, degree of corneal erosion and conjunctival hyperemia via slit lamp biomicroscopy. In addition, questionnaires for the evaluation of eye fatigue and symptoms of a dry eye were completed. The definition of dry eye syndrome was that the tear-break-up-time of one of the eyes was less than 5 seconds, conjunctival injection, or marked corneal erosion. The number of blinks and the duration of blinking were both measured and analyzed at the early and late phases of video-watching. RESULTS: After watching the UHD television in the normal eye group, the tear-break-up-time was significantly decreased (p < 0.001) and the degree of corneal erosion was significantly increased (p = 0.023). However, the subjective symptoms of participants were not aggravated (p = 0.080). There were no significant differences in blinking patterns in the dry eye group. On the other hand, in the normal eye group, the mean blinking time was significantly increased (p = 0.030). CONCLUSIONS: Watching an UHD television changes the tear-break-up-time, degree of corneal erosion, and blinking pattern in normal eyes, which may increase the risk of dry eye syndrome.
