scholarly journals Course for undergraduate students: analysis of the retinal image quality of a human eye model

2014 ◽  
Author(s):  
Maria del Mar Pérez ◽  
Ana Yebra ◽  
Alicia Fernández-Oliveras ◽  
Razvan Ghinea ◽  
Ana M. Ionescu ◽  
...  
Keyword(s):  
Image Quality ◽  
Undergraduate Students ◽  
Retinal Image ◽  
Eye Model ◽  
Human Eye

Aberrations and retinal image quality of the normal human eye

1997 ◽  
Vol 14 (11) ◽  
pp. 2873 ◽  
Author(s):  
Junzhong Liang ◽  
David R. Williams
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Human Eye ◽  
Normal Human

Image quality of the human eye for eccentric entrance pupils

1983 ◽  
Vol 23 (5) ◽  
pp. 573-579 ◽  
Author(s):  
A. Van Meeteren ◽  
C.J.W. Dunnewold
Keyword(s):  
Image Quality ◽  
Human Eye

Influence of Progressive Lenses in the Retinal Image Quality

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 156-156
Author(s):  
J Gispets ◽  
M Arjona ◽  
J Pujol
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Human Subjects ◽  
Optical Quality ◽  
Optical Systems ◽  
Modulation Transfer ◽  
Double Pass ◽  
Progressive Lenses

Progressive lenses (PL) are widely used to correct presbyopia, a visual dysfunction that affects most of the population aged over 40 years. The methods used to evaluate the optical quality of these lenses are mainly based on ray-tracing and optical bench testing. Psychophysical studies based on measurements of the contrast sensitivity function of human subjects also exist. However, all these methods exhibit important limitations because, in general, they do not take into account the optics of the eye. One of the objective techniques that permits evaluation of the retinal image in-vivo is the double pass method (Santamaria et al, 1987 Journal of the Optical Society of America A4 1109 – 1114). It has been possible to study the retinal image quality for different correcting optical systems, such as contact lenses, with this technique (Torrents et al, 1996 Perception25 Supplement, 112 – 113). We studied the retinal image quality of the optical system formed by the eye and a progressive lens. The retinal image quality, characterised by the modulation transfer function (MTF), was measured for different observers as a variety of lines of sight that covered a lens diameter of 50 mm. We show the MTF variation as a function of the lens region and the capacity of this technique to characterise these optical systems.

scholarly journals Retinal image quality in the human eye as a function of the accommodation

1998 ◽  
Vol 38 (19) ◽  
pp. 2897-2907 ◽  
Author(s):  
Norberto López-Gil ◽  
Ignacio Iglesias ◽  
Pablo Artal
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Human Eye

scholarly journals Optical bench simulation for intraocular lenses using field-tracing technology

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0250543
Author(s):  
Seok Ho Song ◽  
In Seok Song ◽  
Se Jin Oh ◽  
Hyeck-Soo Son ◽  
Min Ho Kang
Keyword(s):  
Image Quality ◽  
Ray Tracing ◽  
Retinal Image ◽  
Spherical Aberration ◽  
Experimental Results ◽  
Intraocular Lenses ◽  
Optical Simulation ◽  
Optical Bench ◽  
Eye Model ◽  
Wave Nature

Purpose To evaluate the image quality of intraocular lenses (IOLs) using field-tracing optical simulation and then compare it with the image quality using conventional ray-tracing simulation. Methods We simulated aspheric IOLs with a decenter, tilt, and no misalignment using an aspheric corneal eye model with a positive spherical aberration. The retinal image, Strehl ratio, and modulation transfer function (MTF) were compared between the ray-tracing and field-tracing optical simulation and confirmed by the results reported in an in vitro experiment using the same eye model. Results The retinal image showed interference fringes from target due to diffraction from the object in a field-tracing simulation. When compared with the experimental results, the field tracing represented the experimental results more precisely than ray tracing after passing over 400 μm of the decentration and 4 degrees of the tilt of the IOLs. The MTF values showed similar results for the case of no IOL misalignment in both the field tracing and ray tracing. In the case of the 200-μm decentration or 8-degree tilt of IOL, the field-traced MTF shows lower values than the ray-traced one. Conclusions The field-tracing optical bench simulation is a reliable method to evaluate IOL performance according to the IOL misalignment. It can provide retinal image quality close to real by taking into account the wave nature of light, interference and diffraction to explain to patients having the IOL misalignment.

scholarly journals Intraocular Telescopic System Design: Optical and Visual Simulation in a Human Eye Model

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Georgios Zoulinakis ◽  
Teresa Ferrer-Blasco
Keyword(s):  
Ray Tracing ◽  
Optical Design ◽  
Visual Performance ◽  
Eye Model ◽  
Human Eye ◽  
Telescopic System ◽  
Custom Made ◽  
Design Software ◽  
The Difference

Purpose. To design an intraocular telescopic system (ITS) for magnifying retinal image and to simulate its optical and visual performance after implantation in a human eye model. Methods. Design and simulation were carried out with a ray-tracing and optical design software. Two different ITS were designed, and their visual performance was simulated using the Liou-Brennan eye model. The difference between the ITS was their lenses’ placement in the eye model and their powers. Ray tracing in both centered and decentered situations was carried out for both ITS while visual Strehl ratio (VSOTF) was computed using custom-made MATLAB code. Results. The results show that between 0.4 and 0.8 mm of decentration, the VSOTF does not change much either for far or near target distances. The image projection for these decentrations is in the parafoveal zone, and the quality of the image projected is quite similar. Conclusion. Both systems display similar quality while they differ in size; therefore, the choice between them would need to take into account specific parameters from the patient’s eye. Quality does not change too much between 0.4 and 0.8 mm of decentration for either system which gives flexibility to the clinician to adjust decentration to avoid areas of retinal damage.

scholarly journals Effect of Phenylephrine on the Accommodative System

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
José J. Esteve-Taboada ◽  
Antonio J. Del Águila-Carrasco ◽  
Paula Bernal-Molina ◽  
Teresa Ferrer-Blasco ◽  
Norberto López-Gil ◽  
...  
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Ciliary Muscle ◽  
Depth Of Focus ◽  
Pharmacological Agents ◽  
The Real ◽  
Phenylephrine Hydrochloride ◽  
Main Research ◽  
Human Eye ◽  
Real Effects

Accommodation is controlled by the action of the ciliary muscle and mediated primarily by parasympathetic input through postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia. During accommodation the pupil constricts to increase the depth of focus of the eye and improve retinal image quality. Researchers have traditionally faced the challenge of measuring the accommodative properties of the eye through a small pupil and thus have relied on pharmacological agents to dilate the pupil. Achieving pupil dilation (mydriasis) without affecting the accommodative ability of the eye (cycloplegia) could be useful in many clinical and research contexts. Phenylephrine hydrochloride (PHCl) is a sympathomimetic agent that is used clinically to dilate the pupil. Nevertheless, first investigations suggested some loss of functional accommodation in the human eye after PHCl instillation. Subsequent studies, based on different measurement procedures, obtained contradictory conclusions, causing therefore an unexpected controversy that has been spread almost to the present days. This manuscript reviews and summarizes the main research studies that have been performed to analyze the effect of PHCl on the accommodative system and provides clear conclusions that could help clinicians know the real effects of PHCl on the accommodative system of the human eye.

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