Principle
Accordingtotheprinciplesofphysics,therefractivesystemisarefractivereactionprocessthroughtherefractionandreflectionoftheconvexlens.Inaddition,accordingtotheopticalprinciple,thedistancebetweentheexternalobjectandtheimagingdistanceintheeyeisinverselyproportional.Ontheretinaofanormaleye,theobjectyouseeisclear;itisdifferentwhenyoulookatacloseobject.Asthedistanceoftheobjectbecomessmaller,thelightenteringtheeyewillbediffused,whichleadstotheimagingdistanceintheeye.Instead,itincreases.Atthesametime,theintraocularrefractivesystemcannotclearlyfocustheimageontheretina,sotheobjectsyouseearenotveryclear.Atthistime,undernormalcircumstances,thehumanbodywillmobilizethephysiologicalsynchronousnearreflexadjustmentfunctionoftheeye,andcompleteormakeupforthisprocessthroughtherefractiveadjustmentresponse.Thisprocessiscalledtheadjustmentresponseinmedicine.Inthisphysiologicaladjustmentresponseprocess,thehumaneyewillhavereflexciliarymusclecontractionsoneafteranother;thecurvatureofthelensincreases;therefractivepowerincreases;thevisualaxesofthetwoeyeballsconverge;andthepupilscontract.Throughthisseriesofphysiologicaladjustmentresponses,notonlycanaclearimagebeformedquicklyontheretina,butalsoasymmetricalpositionoftheretinaofthetwoeyescanbeimaged.Then,thephotoreceptorcellsactivatedbytheperceptionsendtheimagedinformationtothevisualcenteroftheoccipitalcortexofthebrainthroughtheneurovisualpathway(visualpathway),andfinallyobtainbinocularvision.Whatyouseeatthistimewillbeveryclear.However,inthisanatomicalandphysiologicaladjustmentresponse,itiscompletelydependentoncomplexchemical,physicalreactions,andadjustmentmechanismstocompleteandmaintain.Then,oncethiscomplexchemical,physicalreaction,andadjustmentmechanismisdamagedbyvariousfactorsinsideandoutsidethebody,itwilldefinitelychangetherefractivesystemofthehumaneye,leadingtorefractiveerrors.Andaccordingtothedifferentconditionsanddegreesofdamagetotherefractiveadjustmentresponsesystem,onewillsufferfromdifferenttypesanddegreesofmyopia,amblyopia,orhyperopia.
