Depth Perception: How Does Your Eyesight Work? - WebMD

Depth perception is how your eyes produce 3D images. Learn about how your eyesight works to focus and make images appear correctly today. MenuNewsReferenceSlideshowsQuizzesVideosFindanOphthalmologistVisionProblemsCommonEyeProblemsPinkeye-ConjunctivitisGlaucomaStyesPupil&IrisProblemsCataractsMacularDegenerationEyelidProblemsChildren'sEyeHealthOcularMigrainesMoreRelatedTopicsEyeHealthReferenceMenuMedicallyReviewedbyDanBrennan, MDonJune15,2021InthisArticleUnderstandingYourEyesightHowDepthPerceptionWorksVisionProblemsAffectingDepthPerceptionYoureyesightallowsyoutofocusonthingsnearandfarasyoulookaroundeachday.Yourbrainandeyesworktogethertomakeouthowfarawaysomethingis.Whenyoulookatsomethingfaraway,youreyesfocusdifferentlythanwhenyoulookatsomethingupclose.Youreyesightdepthperceptionishowimagesappearthree-dimensional(3-D).UnderstandingYourEyesightYoureyeismadeupofdifferentpartsthatallworktogethertohelpyousee.Yourvisionisanimagethatyourbrainprojectsfromtheinformationitreceivesfromtheseparts.Thefirststepinthisprocessisthatlightpassesthroughyourcornea,whichisthefrontlayerofyoureye.Yourcorneaisslightlyroundedsothatlightbendswhenitentersyoureye,allowingforbetterfocus.Thelightentersyoureyethroughthedarkcircleinthecentercalledyourpupil.Thecoloredpartofyoureye—theiris—allowsyourpupiltogrowbiggerorsmallertoletinmoreorlesslight.Afterthat,lightmovesthroughtheinnerpartofyoureyecalledthelens.Yourlensandcorneaworktogethertofocuslightandgiveaclearimagetotheretinaatthebackofyoureye.‌Specialcellsinyourretinaarecalledphotoreceptors,Theyturnthereceivedlightintoelectricalsignalsthatpassthroughyouropticnervetoyourbrain.Yourbrainthenturnsthemessagesreceivedintoimages.HowDepthPerceptionWorksWhenitcomestoyoureyesight,depthperceptionisyourabilitytoseethingsthree-dimensionally.You’reabletodistinguishthelength,width,anddepthofobjectsaswellasestimatehowfartheyarefromyou.‌‌Forthemostaccuratedepthperception,youneedbinocularvision.Thismeansbotheyesfocusonasingleobjectatthesametime.Youmaynoticethatifyoucloseoneeyeortheotherthingsaroundyoulookslightlydifferent.That’sbecausewhenyouusebotheyes,yourbrainmergesthetwoimagestocreateathree-dimensionalview.‌Thisbrain-eyeprocessiscalledconvergencebecauseyoureyeseachlookatobjectsfromslightlydifferentangles.Theresultingimageyourbrainsuccessfullymakesiscalledstereopsis.‌Ifyouonlyhaveasingleeyeorhaveaneyewithimpactvision,yourdepthperceptionmaynotbestrong.Thisisespeciallytruewhenyoufirstbegintorelyonasingleeyeforvisionasyourbrainadjusts.Overtimeyoumayfindthatyourdepthperceptionbecomesmoreaccuratebecauseyourbrainlearnshowtoprocessmonocular(singleeye)vision.Reasonsthatyoumayhaveinaccuratedepthperceptioninclude:BlurryvisioninoneorbothofyoureyesStrabismus,orcrossedeyesAmblyopia,orlazyeyeNerveproblemsinoneofyoureyes‌Traumatooneofyoureyes‌‌Ifyoufindyourselfsquintingortiltingyourheadtoseeobjectsclearly,contactyoureyedoctorforhelp.Theycandoaneyeexamtofindoutthecauseofyourconcerns.Whenitcomestoyourvision,it’simportanttoseektreatmentearlyonsoproblemscanbeaddressedbeforetheygetworse.VisionProblemsAffectingDepthPerceptionBlurredvision.Thisisalsoknownasrefractiveerrors.Youmayhaveblurryvisionforanumberofreasons.Nearsightednesscausesthingsfarawaytoappearblurry,andfarsightednesscausesthingsclosertoyoutoappearblurry.Theseeyeconditionscanaffectyouregardlessofyourageorsex.‌Ifyouare40yearsoldorolder,youmaystruggletoreadthingsupclose.Thisisadifferentconditioncalledpresbyopia.Itisverycommonandaffectsoneinthreepeoplewhoare40yearsoldorolder.Ifyourcorneaismisshapen,itcannotworkwithyourlenstofocuslightproperlytothebackofyoureye.Thisconditioniscalledastigmatism.Youmayneedglassesorcontactstohelpyouseemoreclearlyasthiscanalsobluryourvision.Strabismus.Formostpeople,youreyeslookstraightaheadandmovetogethertolookattheworldaroundyou.However,ifoneorbothofyoureyespointinanotherdirection,itiscalledstrabismus.Individualconditionsthatfallunderthiscategoryinclude:Esotropia,whichiswhenoneorbothofyoureyesturnintowardyournoseExotropia,whichiswhenoneorbothofyoureyesturnoutawayfromyournose Hypertropia,whichiswhenoneorbothofyoureyesturnupwardHypotropia,whichiswhenoneorbothofyoureyesturndownwardIfyoufindoutyouhaveoneoftheseconditionsearlyonandgettreatment,youreyesightcanbecorrected.Ifleftuntreated,theseconditionsmayleadtoalazyeyethatdoesn’tfocus.Lazyeyehappenswhenyourbrainandeyesdon'tworktogetherproperlytoproduceaccurateimages.‌Ifyouseechangesinyoureyesorfindyourselfsquintingortiltingyourheadtoseeobjectsclearly,contactyoureyedoctorforhelp.Theycandoaneyeexamtofindoutthecauseofyourconcerns.Whenitcomestoyourvision,it’simportanttoseektreatmentearlyonsoproblemscanbeaddressedbeforetheygetworse.13ReasonstoCareAboutYourEyeHealthWhatCausesEyeFloaters?WhatIsCornealCross-Linking?WhatIsanIntraocularLensImplant?AreAllergiesAffectingYourEyes?ShouldYouSqueezeaSty?AllAboutPinkeyeLearnaboutcauses,symptoms,andtreatments.WhyYourEyesTwitchSimpleannoyanceorthesignofaproblem?EyeAllergiesSymptoms,triggers,andtreatments.IsYourVisionGettingWorse?Warningsigns,myths,andfacts.ArticleWhatIsaStye?ArticleDryEyes?MeibomianGlandDysfunctionIsaLikelyCulpritArticleSpotsandShadows:WhatAreBenignEyeFloaters?VideoImportanceofRouti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