https://congress.escrs.org/
ESCRS 2026 | The European Society of Cataract and Refractive Surgeons
Jul 8, 2026 - Join ESCRS 2026 for a Congress packed with cutting edge presentations, workshops and more, from top professionals in ophthalmology.
the europeanescrssocietycataractrefractive
https://isrs.org/
Home - International Society of Refractive Surgery
home internationalsocietyrefractivesurgery
https://voldvision.com/
Best Vision Correction Surgeon Orlando & Central FL | Refractive & Ophthalmologic Eye Surgery |...
Vold Vision, lead by renowned ophthalmologist Dr. Steven Vold, is a state-of-the-art eye care facility in Orlando, FL that provides comprehensive vision...
vision correctioncentral flbestsurgeonorlando
https://scholars.cityu.edu.hk/en/publications/development-of-high-refractive-znspvppdmaa-hydrogel-nanocomposite/
Development of high refractive ZnS/PVP/PDMAA hydrogel nanocomposites for artificial cornea implants...
https://vcg.seas.harvard.edu/publications/20020101-acquisition-and-rendering-of-transparent-and-refractive-objects
VCG Harvard | Acquisition and Rendering of Transparent and Refractive Objects
Visual Computing Group at Harvard University led by Hanspeter Pfister.
vcgharvardacquisitionrenderingtransparent
https://researchprofiles.ku.dk/en/publications/endothelial-cell-loss-and-refractive-predictability-in-femtosecon/
Endothelial cell loss and refractive predictability in femtosecond laser-assisted cataract surgery...
https://www.eyenews.uk.com/reviews/journal-reviews/post/refractive-surgery-for-anisometropic-amblyopia
Refractive surgery for anisometropic amblyopia | Eye News
refractive surgeryamblyopiaeyenews
https://laurentjacques.gitlab.io/publication/refractive-index-map-reconstruction-in-optical-deflectometry-using-total-variation-regularization/
Refractive index map reconstruction in optical deflectometry using total-variation regularization |...
refractive indexmapreconstruction
https://eprints.soton.ac.uk/463709/
Investigation of magneto-optical rotation, refractive index and density of some aqueous ionic...
optical rotationrefractive index
https://www.teiclinic.com/
The Eye Institute | Refractive Surgery | Issaquah, WA, USA
The Eye Institute, under Dr. Sandoval's expertise, provides refractive surgery solutions in Issaquah, WA. With advanced techniques like EVO and RLE, patients...
the eye instituterefractive surgeryissaquah wausa
https://pubmed.ncbi.nlm.nih.gov/23680160/
Light levels, refractive development, and myopia--a speculative review
Recent epidemiological evidence in children indicates that time spent outdoors is protective against myopia. Studies in animal models (chick, macaque, tree...
lightlevelsrefractivedevelopmentmyopia
https://profiles.wustl.edu/en/publications/diaphragmatic-discontinuity-associated-with-perihepatic-ascites-a/fingerprints/
Diaphragmatic discontinuity associated with perihepatic ascites: A sonographic refractive artifact...
associated withdiscontinuityascitesrefractiveartifact
https://impact.ornl.gov/en/publications/digital-and-gradient-refractive-index-planar-optics-by-nanoimprin/
Digital and Gradient Refractive Index Planar Optics by Nanoimprinting Mesoporous Silicon - Oak...
refractive index
https://fast.wistia.net/embed/iframe/hj7vyffk3h?seo=false&videoFoam=true
Refractive PRK
refractiveprk
https://pmc.ncbi.nlm.nih.gov/articles/PMC10698524/
Management of Nasya-induced pyrexia in a patient with refractive error and migraine: a case report...
A 23 year old young lady was admitted for Ayurveda treatments of her refractive error coupled with migraine. She was put on Shadbindu Taila Nasya, 24 drops in...
https://airbornescience.nasa.gov/content/Predicting_Real_Refractive_Index_of_Organic_Aerosols_From_Elemental_Composition
Predicting Real Refractive Index of Organic Aerosols From Elemental Composition | NASA Airborne...
refractive index
https://eprints.soton.ac.uk/65815/
Direct measurement of the complex refractive index in the extreme ultraviolet spectral region using...
https://ophthalmologyconferences.org/
Ophthalmology Congress 2026 | Ophthalmology Conferences | Cataract & Refractive Surgery Meeting |...
refractive surgeryophthalmologycongressconferencescataract
https://experts.colorado.edu/display/meshid_C11.744
Refractive Errors | CU Experts | CU Boulder
refractive errorscuexpertsboulder
https://scholars.cityu.edu.hk/en/publications/high-fom-pcf-spr-refractive-index-sensor-based-on-mgfsub2sub-au-d/
High FOM PCF-SPR refractive index sensor based on MgF2-Au double-layer films - CityUHK Scholars
https://www.giss.nasa.gov/pubs/abs/ar06100q.html
NASA GISS: Arking and Rao 1971: Refractive index of aqueous HCl and the clouds of Venus
https://experts.colorado.edu/display/pubid_93422
Sensitivity of Aerosol Refractive Index Retrievals Using Optical Spectroscopy | CU Experts | CU...
refractive indexoptical spectroscopysensitivityaerosol
https://www.nice.org.uk/guidance/ipg164
Photorefractive (laser) surgery for the correction of refractive errors | Guidance | NICE
We have moved interventional procedures guidance 164 to become HealthTech guidance 107. This is to better reflect the NICE HealthTech programme which combines...
laser surgeryfor therefractive errors
https://espo.nasa.gov/crystalface/content/Ultraviolet_and_visible_complex_refractive_indices_of_secondary_organic_material_produced_by
Ultraviolet and visible complex refractive indices of secondary organic material produced by...
https://jsss.copernicus.org/articles/4/209/2015/
JSSS - Refractive index sensing of gases based on a one-dimensional photonic crystal nanocavity
Abstract. Silicon photonic crystal sensors have become very attractive for various optical sensing applications. Using silicon as a material platform provides...
https://www.fda.gov/medical-devices/lasik/fda-approved-lasers-prk-and-other-refractive-surgeries
FDA-Approved Lasers for PRK and Other Refractive Surgeries | FDA
FDA-Approved Lasers for PRK and Other Refractive Surgeries
fda approvedand otherlasersprkrefractive
https://store.astm.org/e1303-95r00.html
E1303 Practice for Refractive Index Detectors Used in Liquid Chromatography
refractive indexpracticedetectorsusedliquid
https://scholars.cityu.edu.hk/en/publications/analysis-of-modal-dispersion-in-plastic-optical-fibres-with-a-w-s/
Analysis of modal dispersion in plastic optical fibres with a W-shaped refractive index - CityUHK...
https://pubmed.ncbi.nlm.nih.gov/31218400/
Refractive surgery in the late adulthood and adolescent age groups
Refractive surgery in the late adulthood population of our cohort was a relatively safe procedure, yet manifesting lower efficacy and requiring more...
refractive surgeryin thelateadulthoodadolescent
https://www.vagelos.columbia.edu/departments-centers/ophthalmology/education/ophthalmology-fellowships-programs/cornea-anterior-segment-and-refractive-surgery-fellowship
Cornea, Anterior Segment, and Refractive Surgery Fellowship | Vagelos College of Physicians and...
Sep 19, 2025 - Columbia offers a world-class fellowship in cornea anterior segment and refractive surgery.
anterior segmentrefractive surgerycollege ofcornea
https://rsu.tilganga.org/
Refractive Surgery Unit | Tilganga Institute of Ophthalmology
refractive surgeryunitinstituteophthalmology
https://open.bu.edu/items/4befb70f-365f-4e75-ae08-04a7433d1097
The determination of refractive indices of dynamic gaseous media by a scanning grid (Dissertation)
In this paper we are concerned with the possibility of improving the field strength of a radiated electromagnetic disturbance. The disturbance is propagated by...
https://infoscience.epfl.ch/entities/publication/9b12cc61-f1f2-4223-82a7-0e97bae0b8b7/statistics
Nanoscale local modification of PMMA refractive index by tip-enhanced femtosecond pulsed laser...
Tip-enhanced optical effects have enabled a wide palette of nanoscale investigation techniques and recently they were successfully used to modify and...
https://scholars.lib.ntu.edu.tw/entities/publication/4021586a-d52d-4dfd-9531-8ecb753ceff7
Gravity-actuated Microfluidic Chip for Urinary Creatinine and Refractive Index Measurement
microfluidic chiprefractive indexgravityactuated
https://scholars.uky.edu/es/publications/refractive-outcomes-with-secondary-intraocular-lens-implantation-/
Refractive outcomes with secondary intraocular lens implantation in children -
intraocular lensrefractiveoutcomessecondaryimplantation
https://www.eyenews.uk.com/reviews/journal-reviews/post/is-laser-refractive-surgery-safe-for-patients-taking-isotretinoin
Is laser refractive surgery safe for patients taking isotretinoin? | Eye News
laser refractive surgeryfor patientssafe
https://inventions.pitt.edu/technologies/high-refractive-index--01215
High Refractive Index Crystalline Colloidal Arrays
Self-assembling ZnS-polystyrene colloidal arrays with high ~2 refractive index enable efficient visible-NIR diffraction for coatings, filters, sensors.
refractive indexhighcrystallinearrays
https://dx-blast.en.made-in-china.com/product/XEOYsyNjluUT/China-A1-BS6088-Refractive-Buffing-Angular-Hard-Bulk-Beads-Round-Ceramic-Sand-Blasted-Sandblasting-Glass-Bead.html
A1 BS6088 Refractive Buffing Angular Hard Bulk Beads Round Ceramic Sand Blasted Sandblasting Glass...
A1 BS6088 Refractive Buffing Angular Hard Bulk Beads Round Ceramic Sand Blasted Sandblasting Glass Bead, Find Details and Price about Metal Abrasives Surface...
https://research.tue.nl/nl/publications/measurement-of-the-complex-refractive-index-of-liquids-in-the-inf/
Measurement of the complex refractive index of liquids in the infrared using spectroscopic...
of therefractive indexmeasurementcomplex
https://refractive.scot/
Refractive Collective | Film Makers & Digital Artists
Refractive is an independent artist led collective of film makers and digital artists.
film makersrefractivecollectivedigitalartists
https://isprs-archives.copernicus.org/articles/XLVIII-2-W10-2025/107/2025/
ISPRS-Archives - Exploring the Potential of Refractive NeRFs for Photogrammetric Bathymetry - First...
isprs archivesexploring the
https://meetings-archive.aps.org/mar/2008/h35/9/
A method for determining refractive indices of epilayers of multi-structure active layer -...
The refractive indices of bulk and epitaxially grown materials differ. Besides, it is very difficult to experimentally determine and theoretically calculate the
https://eprints.soton.ac.uk/176665/
Using the photoinduced reversible refractive-index change of an azobenzene co-polymer to...
https://www.scirp.org/reference/ReferencesPapers?ReferenceID=2391056
Chen, H., Kou, X., Yang, Z., Ni, W. and Wang, J. (2008) Shape- and Size-Dependent Refractive Index...
Chen, H., Kou, X., Yang, Z., Ni, W. and Wang, J. (2008) Shape- and Size-Dependent Refractive Index Sensitivity of Gold Nanoparticles. Langmuir, 24, 5233-5237.
https://www.research.fsu.edu/research-offices/oc/technologies/thiol-ene-polymer-metal-oxide-nanoparticle-high-refractive-index-composites/
Thiol-ene polymer metal oxide nanoparticle high refractive index composites | FSU Office of Research
https://scholars.lib.ntu.edu.tw/entities/publication/b4dd8b71-edac-4c0f-8cb8-6ba3045af1ec
Nonlinear Refractive-Index Near Half the Band Gap in AlGaAs
refractive indexthe bandnonlinearhalfgap
https://research.vu.nl/en/publications/the-prevalence-of-refractive-errors-among-people-with-multiple-di/
The prevalence of refractive errors among people with multiple disabilities. A file study into 1300...
https://publikationen.bibliothek.kit.edu/1000063354
Development and Characterization of Adjustable Refractive Inde...
developmentcharacterizationadjustablerefractiveinde
https://research.ibm.com/publications/refractive-index-of-amorphous-carbon-near-its-k-edge
Refractive index of amorphous carbon near its K-edge for Applied Optics - IBM Research
Refractive index of amorphous carbon near its K-edge for Applied Optics by Eberhard Spiller
https://blogs.bmj.com/bmjgh/2025/09/04/eliminating-uncorrected-refractive-error-by-2030-lmics-need-policies-and-a-roadmap-not-just-intentions/
Eliminating Uncorrected Refractive Error by 2030: LMICs Need Policies and a Roadmap, Not Just...
Sep 4, 2025 - Tackling uncorrected refractive error in LMICs requires more than intent; this blog proposes a five phase framework to achieve the 2030 target for refractive...
https://ub01.uni-tuebingen.de/xmlui/handle/10900/101512
Refractive adaptation and efficacy of occlusion therapy in untreated amblyopic patients aged 12 to...
https://pubs.rsc.org/en/content/articlelanding/2020/CP/C9CP06395A
Measurement of the fluorescence lifetime of GFP in high refractive index levitated droplets using...
Green fluorescent protein (GFP) is a widely used fluorescent probe in the life sciences and biosciences due to its high quantum yield and extinction...
https://laser4sight.com/
Northlake Eye Center | Leaders in Laser Refractive Surgery and Providers of Quality Eye Care in...
For LASIK in Slidell, Louisiana, patients trust Northlake Eye Center for our experienced surgeons and excellent customer service.
laser refractive surgery
https://pmc.ncbi.nlm.nih.gov/articles/PMC8699644/
Recent trends of refractive surgery rate and detailed analysis of subjects with refractive surgery:...
The present study was conducted to investigate recent trends of refractive surgery rates and analyze subjects undergoing refractive surgery using large-scale...
recent trendsrefractive surgerydetailed analysis
https://experts.arizona.edu/en/publications/composition-dependence-and-reversibility-of-photoinduced-refracti/
Composition dependence and reversibility of photoinduced refractive index changes in chalcogenide...
refractive indexcompositiondependencereversibility
https://drive.google.com/file/d/173QmvkvuKxzDB75iRngZdo23on-r-ZiZ/view?usp=sharing
43Vision Refractive Lens Exchange Oklahoma City - Call Us (405) 883-4343 Links - About.pdf - Google...
https://sites.google.com/view/43vision/refractive-lens-exchange-oklahoma-city 43Vision is the first vision correction center dedicated to treating patients age...
https://eyex.thinkific.com/courses/refractive-surgery-today-and-the-future
Session 15: Refractive Surgery: Today and The Future
Dr. Ray Stein discusses the subject of refractive surgery and how it is evolving. He discusses present day technology and patient-based scenarios and offers...
refractive surgeryand thesessiontodayfuture
https://www.eyenews.uk.com/reviews/journal-reviews/post/occlusion-vs-video-gaming-for-treatment-of-refractive-anisometropic-amblyopia
Occlusion vs. video gaming for treatment of refractive / anisometropic amblyopia | Eye News
video gaming
https://research-portal.st-andrews.ac.uk/en/publications/indirect-transitions-of-a-signal-interacting-with-a-moving-refrac/
Indirect transitions of a signal interacting with a moving refractive index front - University of...
of a
https://regencyeye.com/
Refractive eye surgery based in the heart of Manchester
Jan 30, 2026 - Regency Eye Hospital offers refractive eye surgery, cataract surgery, Lens replacement surgery in heart of Manchester UK.
refractive eye surgeryin the heartbasedmanchester
https://nrc-publications.canada.ca/eng/view/object/?id=84addf98-65c6-4795-8afd-f21befd559d8
Femtosecond laser-induced refractive index modification in multicomponent glasses - NRC...
Femtosecond laser-induced refractive index modification in multicomponent glasses
femtosecond laserrefractive indexinducedmodificationmulticomponent
https://pubmed.ncbi.nlm.nih.gov/20399936/
Refractive surgery in children: treatment options, outcomes, and controversies
Refractive surgery in children: treatment options, outcomes, and controversies
surgery in childrentreatment optionsrefractiveoutcomescontroversies
https://acp.copernicus.org/articles/13/531/2013/
ACP - Wavelength and NOx dependent complex refractive index of SOAs generated from the...
https://experts.arizona.edu/en/publications/three-wave-interaction-in-negative-refractive-index-materials-wit/
Three wave interaction in negative refractive index materials with quadratic nonlinearity -...
three waverefractive indexinteractionnegative
https://www.eyenews.uk.com/events/event/refractive-surgery-certificate-one-day-revision-course
Refractive Surgery Certificate One-Day Revision Course | Eye News
refractive surgeryone dayrevision coursecertificateeye
https://researchconnect.buffalo.edu/en/publications/refractive-indices-of-soot-particles-deduced-from-in-situ-laser-l/
Refractive indices of soot particles deduced from in-situ laser light scattering measurements -...
https://acp.copernicus.org/articles/14/11093/2014/acp-14-11093-2014-discussion.html
ACP - Peer review - Variability of the infrared complex refractive index of African mineral dust:...
https://scholars.cityu.edu.hk/en/publications/protozoon-classifications-based-on-size-shape-and-refractive-inde/
Protozoon classifications based on size, shape and refractive index using on-chip immersion...
based on
https://pmc.ncbi.nlm.nih.gov/articles/PMC6494484/
Optical correction of refractive error for preventing and treating eye symptoms in computer users -...
Computer users frequently complain about problems with seeing and functioning of the eyes. Asthenopia is a term generally used to describe symptoms related to...
https://open.library.emory.edu/concern/publications/a0d496a5-430e-4adc-a8ed-3440a75b80f0
Topography-Guided Refractive Astigmatism Outcomes: Predictions Comparing Three Different...
Topography-Guided Refractive Astigmatism Outcomes: Predictions Comparing Three Different Programming Methods
topographyguidedrefractiveastigmatismoutcomes
https://nrc-publications.canada.ca/eng/view/object/?id=552f6682-a6ea-41df-97ca-9cac4e9af953
Monte Carlo investigation of refractive index gas thermometry uncertainties - NRC Publications...
Monte Carlo investigation of refractive index gas thermometry uncertainties
monte carlorefractive indexinvestigation
https://experts.arizona.edu/en/publications/intraocular-pressure-ethnicity-and-refractive-error/
Intraocular pressure, ethnicity, and refractive error - University of Arizona
intraocular pressurerefractive erroruniversity ofethnicityarizona
https://experts.arizona.edu/en/publications/early-childhood-refractive-error-and-parental-history-of-myopia-a/
Early childhood refractive error and parental history of myopia as predictors of myopia -...
early childhoodrefractive errorhistory of
https://www.mdpi.com/1424-8220/23/5/2675
High-Precision 3D Reconstruction Study with Emphasis on Refractive Calibration of GelStereo-Type...
GelStereo sensing technology is capable of performing three-dimensional (3D) contact shape measurement under various contact structures such as bionic curved...
https://pubmed.ncbi.nlm.nih.gov/30905725/
Refractive Error Has Minimal Influence on the Risk of Age-Related Macular Degeneration: A Mendelian...
Under the assumption of a linear relationship between refractive error and the risk of AMD, myopia and hyperopia only minimally influence the causal risk for...
https://www.imm.cnr.it/publications/refractive-index-tailoring-congruent-lithium-niobate-ion-implantation
Refractive index tailoring in congruent Lithium Niobate by ion implantation | IMM Container
refractive index
https://nrc-publications.canada.ca/eng/view/object/?id=90d251a9-c780-4635-b4b3-afe49e5bee79
Refractive index determination and air-void characterization of BNNT assembly using optical fiber...
Refractive index determination and air-void characterization of BNNT assembly using optical fiber bragg grating sensors
https://miun.diva-portal.org/smash/record.jsf?pid=diva2:1336514
Determining the complex refractive index of cellulose nanocrystals by combination of Beer-Lambert...
the complexrefractive index
https://experts.arizona.edu/en/publications/optical-dispersion-of-the-refractive-index-modulation-in-low-tg-p/
Optical dispersion of the refractive index modulation in low Tg photorefractive polymers -...
of therefractive index
https://dspace.rpi.edu/items/23b68081-1c27-4103-b2a9-241605a7e476
Optical pulse dynamics in active media with negative refractive index
active mediaopticalpulsedynamicsnegative
https://meetings-archive.aps.org/mar/2006/g16/7/
A model for the influence of granularity in a negative refractive index metamaterial lens -...
An important goal in building a negative refractive index metamaterial lens at optical frequencies is the achievement of sub-wavelength image resolution. In ass
https://rp-handbooks.sydney.edu.au/handbooks/archive/2014/medicine/postgraduate/coursework_ah/cataract_refractive_surgery.shtml.html
Cataract and Refractive Surgery - Sydney Medical School - The University of Sydney
refractive surgerymedical schoolthe universitycataractsydney
https://refractivesurgery.com/
Home - THE MCGILL REFRACTIVE SURGERY RESEARCH UNIT
Jul 10, 2025 - The McGill Refractive Surgery Research Unit, with its unique access to large databases, employs big data analytics to gain clinical insights into LASIK, PRK,...
refractive surgerymcgillresearchunit
https://pubmed.ncbi.nlm.nih.gov/37009857/
Refractive Outcome After Corneal Lenticule Implantation Ex Vivo Non-Human Study
Intrastromal corneal lenticule implantation induces changes in corneal refractive parameters. In both groups, the implantation induced a significant increase...
ex vivorefractiveoutcomecorneal
https://pubmed.ncbi.nlm.nih.gov/29633784/
Optical correction of refractive error for preventing and treating eye symptoms in computer users
There is low to very low quality evidence that providing computer users with progressive computer glasses does not lead to a considerable decrease in problems...
https://iris.cnr.it/handle/20.500.14243/124704
Magnetically-modulated refractive index of a magnetic fluid film based on cigar shaped ferrite...
https://ldaeyeclinic.com/
Cataract and Refractive Surgery - de Klerk Eye Surgery, Manchester
Jun 8, 2023 - We specialise in cataract extraction surgery and laser refractive eye surgery
refractive surgeryde klerkcataracteyemanchester
https://pure.psu.edu/en/publications/comment-on-negative-refractive-index-in-artificial-metamaterials/
Comment on "negative refractive index in artificial metamaterials" - Penn State
refractive indexcommentnegativeartificialmetamaterials
https://publikationen.bibliothek.kit.edu/240072865
Measurements with compound refractive lenses at the 'BAMline'
at themeasurementscompoundrefractivelenses
https://pure.psu.edu/en/publications/temperature-dependence-of-refractive-index-in-blue-phase-liquid-c/
Temperature dependence of refractive index in blue phase liquid crystals - Penn State
temperature dependencerefractive index
https://www.cochrane.org/zh-hans/evidence/CD012946_effectiveness-and-safety-two-types-tools-used-lasik-type-refractive-surgery-nearsightedness
Effectiveness and safety of two types of tools used in LASIK (a type of refractive surgery) for...
https://nrc-publications.canada.ca/fra/voir/objet/?id=0b8ac3b6-311e-4780-a811-b56063f762cb
Diffusion study evaluation in tailored gratings recorded in photopolymer glass with high refractive...
Diffusion study evaluation in tailored gratings recorded in photopolymer glass with high refractive index species
https://vivo.colorado.edu/display/pubid_103883
Multiangle light-scattering measurements of refractive index of submicron atmospheric particles |...
light scatteringrefractive indexmeasurementsatmosphericparticles
https://experts.arizona.edu/en/publications/nonlinear-surface-waves-in-negative-refractive-index-thin-films-3/
Nonlinear surface waves in negative refractive index thin films - University of Arizona
refractive index
https://www.mdpi.com/1424-8220/20/15/4125
A Nanostructure with Defect Based on Fano Resonance for Application on Refractive-Index and...
Herein, a nanosensor structure is proposed, which comprises metal-insulator-metal (MIM) waveguide with stub and circular ring cavity with a stub (CRCS). The...
https://www.wolframalpha.com/input/?i=Water+refractive+index
Water refractive index - Wolfram|Alpha
refractive indexwaterwolframalpha
https://pmc.ncbi.nlm.nih.gov/articles/PMC9584055/
Contact Lens Safety for the Correction of Refractive Error in Healthy Eyes - PMC
Contact lenses are a safe and effective method for correction of refractive error and worn by an estimated 45 million Americans. Because of the widespread...
https://publikationen.uni-tuebingen.de/xmlui/handle/10900/66354
Refractive errors, visual impairment, and the use of low-vision devices in albinism in Malawi
https://pubmed.ncbi.nlm.nih.gov/37381226/
Multi working mode SPR chip laboratory for high refractive index detection
The Fiber SPR chip laboratory has become a popular choice in biochemical detection. To meet the needs of different kinds of analytes for the detection range...
working moderefractive indexmultisprchip
https://espo.nasa.gov/cpex-aw/content/Contrasting_aerosol_refractive_index_and_hygroscopicity_in_the_inflow_and_outflow_of_deep
Contrasting aerosol refractive index and hygroscopicity in the inflow and outflow of deep...
refractive index