defects of vision

DEFECTS OF VISION Ushakumari.V Christ nagar senior secondary school Thiruvallom

Upload: ushavpillai

Post on 22-May-2015

599 views

Category:

Documents

0 download

Report

Download

Tags:

Embed Size (px):

TRANSCRIPT

DEFECTS OF VISION

Ushakumari.VChrist nagar senior secondary school

Thiruvallom

EYES- OUR WINDOWS TO THE WORLD!

Spectacles

?????WHY

SO ????

DEFECTS OF VISION When normal

functioning of the eye is affected , it results in defects of vision

Mainly 2 types Myopia (short

sightedness) Hypermetropia

(long sightedness)

NORMAL EYE

In a normal eye , light passes through the cornea , and the image is focused by the lens on the retina

WHAT IS THE DIFFICULY HERE????????

MYOPIA- NEARSIGHTEDNESS

A person can see nearby objects clearly and distinctly but cannot see far away objects clearly.

In myopic eye ,the image is formed in front of the retina.

Caused by two reasons: Elongation of the eyeball so images are focused in

front of the retina Decrease in the focal length of eye lens

Correction: by using a concave lens of appropriate power.

MYOPIC EYE

MYOPIC EYE-IMAGE FORMATION

MYOPIC EYE – RAY DIAGRAM & CORRECTION USING CONCAVE LENS

CAN YOU SEE PROPERLY ?????

HYPERMETROPIA – FAR SIGHTEDNESS

The person can see distant objects clearly and distinctly but cannot see nearby objects clearly

The image is focused behind the retina

Main causes are : Shortening of the eyeball So the images are

focused behind the retina Increase in focal length of the eye lens

Correction: by using a convex lens of appropriate power

HYPERMETROPIC EYE

HYPERMETROPIC EYE – IMAGE FORMATION

HYPERMETROPIC EYE – RAY DIAGRAM AND CORRECTION USING CONVEX LENS

SUMMING UP ….

Detection of Bare PCB Defects by Image Subtraction Method ... · Detection of Bare PCB Defects by Image Subtraction Method using Machine Vision Ajay Pal Singh Chauhan, Sharat Chandra

Categorisation of Defects

Vision Defects Screening in Children Final 2013

Vision Express User Manualmanufacturer’s warranties.) Vision does not warrant defects caused by a failure to provide a suitable environment for the system, by unauthorized attachments,

General Science and Technology · 12.Refraction by Lenses 42 13.The Camera and the Eye 43 14. Colour Vision 44 15.Colour of Objects 44 16.Defects of Vision and their Correction44

Human Eye and Defects of Vision€¦ · ‘Human Eye’ is the organ of vision of the human body that enables us to see. The human eye(s) are located in the specialized sockets carved

Lecture 63 Ischemic Stroke & Intracerebral Hemorrhage Halpape … · • Double vision • Visual defects • Aphasia (inability to comprehend or produce language) • Dysarthria

1© Manhattan Press (H.K.) Ltd. The human eye Visual defects and their corrections Visual defects and their corrections 12.3 Properties of vision Visual

Acquired Color Vision Defects in Chronic Heavy Smoking · Acquired Color Vision Defects in ... smoked more than 20 cigarettes/day and had a score ... Acquired Color Vision Defects

Vision defects and corrective lenses

Titmus V4 Vision Screener - Intermedic Group · 2017-02-11 · Warranty The Titmus V4 Vision Screener has a warranty for a period of two (2) years against defects in materials and

National Center on Birth Defects and Developmental … · 1 CDC’s National Center on Birth Defects and Developmental Disabilities Strategic Plan February 10, 2011 Our Vision and

Computer Vision-based Fabric Defect Detection: A Surveycsajaykr/myhome/file/tie08.pdf · Computer Vision-based Fabric Defect Detection: A Survey ... of real fabric defects is

· 2008-01-14 · DEFECTS FINISH DEFECTS NECK DEFECTS SHOULDER DEFECTS BODY DEFECTS BASE DEFECTS Innovative Inspection Technology Guide BROKEN WARE Ware which is cracked or broken

Computer Vision and Normalizing Flow Based Defect DetectionComputer vision, Visual inspection, Deep Neural Network, YOLO I. INTRODUCTION Surface defects have a signiﬁcant impact

Validation of Foundry Process for Aluminum Parts with … · vitrification (deposit of sand). Other defects (defects misrun, blowholes, turbulent flow and Other defects (defects misrun,

defects point defects line defects planar defects€¦ · a two-dimensional surface in the crystal. There can also be three-dimensional defects such as voids. Crystalline Defects:

Norms of restrictions of plywood processing defects in ...€¦ · Norms of restrictions of plywood processing defects in accordance with the requirements of STO ... Biological defects

Machine Vision Inspection of Railroad Track - AREMA · machine vision to detect irregularities and defects in wood-tie fasteners, rail anchors, crib ballast, and turnout components

Crystal defects linear defects (dislocations)

FirstFirst--principles simulations of defects principles ...FirstFirst--principles simulations of defects principles simulations of defects in oxides and nitridesin oxides and nitrides

Coding Defects of Bilateral Symmetry · Coding Defects of Bilateral Symmetry Angela Scheuerle, M.D. University of Texas: Southwestern Medical Center Texas Birth Defects Epidemiology

DEFECTS IN CRYSTALSeacharya.inflibnet.ac.in/data-server/eacharya... · DEFECTS IN CRYSTALS Point defects 0D Line defects 1D Surface Imperfections 2D Volume Defects 3D MATERIALS SCIENCE

Signs of Eye Disease - Auckland€¦ · Visual field defects . Tunnel vision . Visual field defects . Eye movements . Eye movements . Pupil reactions • Responses to light •Direct

REVIEW OF THE OFFICE OF DEFECTS INVESTIGATION · PDF fileSafety Administration (NHTSA) Office of Defects Investigation (ODI). ... Review of the Office of Defects Investigation National

024-044 Spectral Saturation and Its Relation to Color-Vision Defects

Molding Defects, Causes, & Corrective Actions...Molding Defects, Causes, Corrective Actions Possible Molding Defects Possible Molding Defects Possible Molding Defects Defect Description

Defects in solids: Point defects and line defects

· Web viewCoated glass: For point defects, comply with ASTM C1376-15 section 6.1 (vision glass) or 6.2 (overhead glass) as appropriate for the glazing application. For vision glass

Research on the robot vision system for Detecting defects ...wseas.us/e-library/conferences/2007hangzhou/papers/560-272.pdf · Research on the robot vision system for Detecting defects

Prevention of Refractive Defects of Vision by Means of Evolutionary Medicine Giacinto Libertini

defects point defects line defects planar defectsuotechnology.edu.iq/.../lectures/2c/3-Materials_prperties3.pdf · Crystalline Defects: Imperfections or defects: Any deviation from

A Vision Based System for High Precision Online Fabric ... · PDF fileA Vision Based System for High Precision Online Fabric Defect Detection ... Defects appear in various ... close

Eliminating Defects and Tightening the Quality ... · PDF fileNew Printing Technology with Inline Machine Vision Inspection Eliminating Defects and Tightening the Quality Requirements

Principles of Reconstructive Surgery of Defects of …codental.uobaghdad.edu.iq/.../01/recontructive-surgery-1.pdfPrinciples of Reconstructive Surgery of Defects of the Jaws Defects

defects of vision

Documents

normal eye

myopic eyeimage formation

hypermetropic eye ray

retina increase

nearby objects

distant objects

defects of vision ushakumari

retina main causes