The study explored the methods of determining the diameter of clear optic of intraocular lenses by analyzing the design principles and influencing factors of clear optic. Measure and compare the clear optic diameters of intraocular lenses from -10.0 D to 36.0 D respectively. The measurement results of the two methods have good consistency and can be used in the measurement of clear optic. But considering the accuracy and convenience of actual measurement, profile projector measurement principle is more suitable for conventional mass production testing. The Schlieren technique method can provide more useful information in product development and feature description stage, and can be used as an auxiliary verification method for clear optic diameter measurement.
Eye ; Lenses, Intraocular ; Optics and Photonics ; Prosthesis Design

Animals ; Brain ; physiology ; Consciousness ; physiology ; Humans ; Mice ; Neurotransmitter Agents ; physiology ; Optics and Photonics ; Synaptic Transmission ; physiology

BACKGROUND: Parallel-polarized light (PPL) photography evaluates skin characteristics by analyzing light reflections from the skin surface. OBJECTIVE: The aim of this study was to determine the significance of quantitative analysis of PPL images in rosacea patients, and to provide a new objective evaluation method for use in clinical research and practice. METHODS: A total of 49 rosacea patients were enrolled. PPL images using green and white light emitting diodes (LEDs) were taken of the lesion and an adjacent normal area. The values from the PPL images were converted to CIELAB coordinates: L* corresponding to the brightness, a* to the red and green intensities, and b* to the yellow and blue intensities. RESULTS: A standard grading system showed negative correlations with L* (r=−0.67862, p=0.0108) and b* (r=−0.67862, p=0.0108), and a positive correlation with a* (r=0.64194, p=0.0180) with the green LEDs for papulopustular rosacea (PPR) types. The xerosis severity scale showed a positive correlation with L* (r=0.36709, p=0.0276) and a negative correlation with b* (r=−0.33068, p=0.0489) with the white LEDs for erythematotelangiectatic rosacea (ETR) types. In the ETR types, there was brighter lesional and normal skin with white LEDs and a higher score on the xerosis severity scale than the PPR types. CONCLUSION: This technique using PPL images is applicable to the quantitative and objective assessment of rosacea in clinical settings. In addition, the two main subtypes of ETR and PPR are distinct entities visually and optically.
Humans ; Methods ; Optics and Photonics ; Photography ; Rosacea* ; Skin

Optical cochlear implant has been occuring as a new cochlear implant which utilizes laser pulses to stimulate hearing. Compared to electronic cochlear implant, it has demonstrated higher spatial selectivity and less radiation scattering, which could lead to higher fidelity cochlear prostheses. At present, most investigations have focused on experiments in vivo. Although a lot of exciting results have been obtained, the mechanisms of laser stimulation is still open. In this paper, a brief review on the recent new findings of optical cochlear implant is given, and possible mechanisms are discussed. In the end, new experimental proposals are suggested which could help to explore the mechanisms of laser-cochlea stimulation.
Cochlear Implantation ; Cochlear Implants ; Hearing Loss ; rehabilitation ; Humans ; Lasers ; Optics and Photonics

OBJECTIVETo explore the characteristics of light propagation along the Pericardium Meridian and its surrounding areas at human wrist by using optical experiment and Monte Carlo method.

METHODSAn experiment was carried out to obtain the distribution of diffuse light on Pericardium Meridian line and its surrounding areas at the wrist, and then a simplified model based on the anatomical structure was proposed to simulate the light transportation within the same area by using Monte Carlo method.

RESULTSThe experimental results showed strong accordance with the Monte Carlo simulation that the light propagation along the Pericardium Meridian had an advantage over its surrounding areas at the wrist.

CONCLUSIONThe advantage of light transport along Pericardium Merdian line was related to components and structure of tissue, also the anatomical structure of the area that the Pericardium Meridian line runs.

Diffusion ; Humans ; Light ; Meridians ; Models, Theoretical ; Monte Carlo Method ; Optics and Photonics ; methods ; Pericardium ; physiology ; Wrist ; physiology

PURPOSE: To evaluate the accuracy of postoperative refractive outcomes of combined phacovitrectomy for epiretinal membrane (ERM) in comparison to cataract surgery alone. MATERIALS AND METHODS: Thirty-nine eyes that underwent combined phacovitrectomy with intraocular lens (IOL) implantation for cataract and ERM (combined surgery group) and 39 eyes that received phacoemulsification for cataract (control group) were analyzed, retrospectively. The predicted preoperative refractive aim was compared with the results of postoperative refraction. RESULTS: In the combined surgery group, refractive prediction error by A-scan and IOLMaster were -0.305+/-0.717 diopters (D) and -0.356+/-0.639 D, respectively, compared to 0.215+/-0.541 and 0.077+/-0.529 in the control group, showing significantly more myopic change compared to the control group (p=0.001 and p=0.002, respectively). Within each group, there was no statistically significant difference in refractive prediction error between A-scan and IOLMaster (all p>0.05). IOL power calculation using adjusted A-scan measurement of axial length based on the macular thickness of the normal contralateral eye still resulted in significant postoperative refractive error (all p<0.05). Postoperative refraction calculated with adjusted axial length based on actual postoperative central foveal thickness change showed the closest value to the actual postoperative achieved refraction (p=0.599). CONCLUSION: Combined phacovitrectomy for ERM resulted in significantly more myopic shift of postoperative refraction, compared to the cataract surgery alone, for both A-scan and IOLMaster. To improve the accuracy of IOL power estimation in eyes with cataract and ERM, sequential surgery for ERM and cataract may need to be considered.
Aged ; Biometry/methods ; Case-Control Studies ; Cataract Extraction ; Epiretinal Membrane/*surgery ; Eye ; Female ; Humans ; *Lens Implantation, Intraocular ; *Lenses, Intraocular ; Male ; Optics and Photonics ; Phacoemulsification/*methods ; Postoperative Period ; Refraction, Ocular/physiology ; Retrospective Studies ; Treatment Outcome ; Vision Tests ; Visual Acuity ; Vitrectomy/*methods

In this paper, it was studied how physics affected development of optometry in the United States, from aspects of formation and academization of optometry. It was also revealed that history of optometry was analogous to history of engineering. Optics in the 19th century was divided into electromagnetic study of light and visual optics. Development of the visual optics promoted professionalization of ophthalmology that had already started in the 18th century. The visual optics also stimulated formation of optometry and optometrists body in the late 19th century of the United States. The American optometrists body were originated from opticians who had studied visual optics. Publication of several English academic textbooks on visual optics induced appearance of educated opticians (and jewelers). They acquired a right to do the eye examination in the early 20th century after C. F. Prentice's trial in 1897, evolving into optometrists. The opticians could be considered as craftsmen, and they were divided into (dispensing) opticians and optometrists. Such history of American optometrists body is analogous to that of engineers body in the viewpoints of craftsmen origin and separation from craftsmen. Engineers were also originated from educated craftsmen, but were separated from craftsmen when engineering was built up. Education system and academization of optometry was strongly influenced by physics, too. When college education of optometry started at American universities, it was not belonged to medical school but to physics department. Physics and optics were of great importance in curriculum, and early faculty members were mostly physicists. Optometry was academized in the 1920s by the college education, standardization of curriculum, and formation of the American Academy of Optometry. This is also analogous to history of engineering, which was academized by natural sciences, especially by mathematics and physics. The reason why optometry was academized not by medicine but by physics is because ophthalmologists did not have conciliatory attitudes to optometry education. Optometry became independent of physics from the 1930s to the 1940s. Optometric researches concentrated on binocular vision that is not included to discipline of physics, and faculty members who majored in optometry increased, so that optometry departments and graduate schools were established around 1940. Such independence from natural sciences after academization also resembles history of engineering. On the contrary, history of optometry was different from history of ophthalmology in several aspects. Ophthalmology had already been formed in the 18th century before development of visual optics, and was not academized by visual optics. Ophthalmologists body were not originated from craftsmen, and were not separated from craftsmen. History of optometry in the United States from the late 19th to the mid 20th century is analogous to history of engineering rather than history of medicine, though optometry is a medical discipline.
History, 19th Century ; History, 20th Century ; Humans ; Ophthalmology/history ; Optics and Photonics/history ; Optometry/*history ; Physics/*history ; United States

Dental impressions are widely used in the field of oral restoration. The materials are used for making impression in oral cavity. In order to measure the thickness of impression for reference in clinic, the real impressions are taken as the object for studying. Through optical method, charge-coupled device (CCD) is used for collecting the grey image of cutting section of the impressions which are located in the same plane with steel dividing ruler. According to convert relationship between dividing ruler and pixels collecting grey image, the thickness of impression specimens can be obtained. The results show that the optical method used for measuring thickness is feasible to the task and the precision can reach micro dimension. The experiment method and technique can also be provided for measuring thickness of similar tissue engineering materials.
Dental Impression Materials ; Dental Models ; Humans ; Materials Testing ; Optics and Photonics

In order to study the light propagation in biological tissue, we analyzed the divergent beam propagation in turbid medium. We set up a Monte Carlo simulation model for simulating the divergent beam propagation in a semi-infinite bio-tissue. Using this model, we studied the absorbed photon density with different tissue parameters in the case of a divergent beam injecting the tissue. The simulation results showed that the rules of optical propagation in the tissue were found and further the results also suggested that the diagnosis and treatment of the light could refer to the rules of optical propagation.
Computer Simulation ; Light ; Models, Biological ; Monte Carlo Method ; Optics and Photonics ; Scattering, Radiation

PURPOSE: To evaluate the predictability of intraocular lens (IOL) power calculations using the IOLMaster and four different IOL power calculation formulas (Haigis, Hoffer Q, SRK II, and SRK/T) for cataract surgery in eyes with a short axial length (AL). METHODS: The present study was a retrospective comparative analysis which included 25 eyes with an AL shorter than 22.0 mm that underwent uneventful phacoemulsification with IOL implantation from July 2007 to December 2008 at Seoul National University Boramae Hospital. Preoperative AL and keratometric power were measured by the IOLMaster, and power of the implanted IOL was determined using Haigis, Hoffer Q, SRK II, and SRK/T formulas. Postoperative refractive errors two months after surgery were measured using automatic refracto-keratometry (Nidek) and were compared with the predicted postoperative power. The mean absolute error (MAE) was defined as the average of the absolute value of the difference between actual and predicted spherical equivalences of postoperative refractive error. RESULTS: The MAE was smallest with the Haigis formula (0.37 +/- 0.26 diopter [D]), followed by those of SRK/T (0.53 +/- 0.25 D), SRK II (0.56 +/- 0.20 D), and Hoffer Q (0.62 +/- 0.16 D) in 25 eyes with an AL shorter than 22.0 mm. The proportion with an absolute error (AE) of less than 1 D was greatest in the Haigis formula (96%), followed by those in the SRK II (88%), SRK-T (84%), and Hoffer Q (80%). CONCLUSIONS: The MAE was less than 0.7 D and the proportion of AE less than 1 D was more than 80% in all formulas. The IOL power calculation using the Haigis formula showed the best results for postoperative power prediction in short eyes.
Aged ; Aged, 80 and over ; Female ; Humans ; Lens Implantation, Intraocular ; *Lenses, Intraocular ; Male ; Middle Aged ; *Optics and Photonics ; Phacoemulsification ; Postoperative Period ; Refractive Errors/diagnosis/physiopathology ; Retrospective Studies