Cikakken hoton ido da abinda ya kunsa

A cikin muhallin da kake yanzu duba gefenka watakila zaka ga kujera, mota, mashin, dutse, bishiya da sauransu. A duk lokacin da idanuwanka suka tsinkayi abu to kasani cewa kwakwalwarka ce ke da alhakin iya tantance abinda idanuwanka suka gani.

Mafi akasarin mutane basu dauki gani a bakin komai ba, saboda rashin wahalar aiwatar dashi. Cikin kankanin lokaci idanuwanka zasu iya tsinkayar abubuwa fiye da dubu a lokaci guda. Amma abin tambaya a nan ta yaya muke iya gani da idanuwa har kwakwalwarmu take iya tantance abinda muka gani?

Kamar yadda muka sani

A gangar jikinmu akwai wasu muhimman gabobi guda biyar da suke taimaka mana wajen iya fahimtar abubuwan dake kewaye damu a muhallinmu, wadannan gabobi sune:

1. Gabar sauraro (Kunne)
2. Gabar tabawa (Fata)
3. Gabar Sunsunawa (Hanci)
4. Gabar gani (Ido)
5. Gabar dandano (Harshe)

Kowace gaba tana da matukar muhimmanci a jikin dan adam, sai dai yawancin mutane suna ganin cewa rasa gabar gani wato ido itace babbar matsalar da dan adam zai fuskanci rayuwa mafi muni idan ya rasata.

Idan baka gani ta yaya zaka iya kallon talbijin, ta yaya zaka iya kaucewa hatsari kamar afkawa rijiya, titi, wuta da sauransu. Sai dai duk da haka akan sami wasu mutane suna rayuwa batare da wannan gaba ba.

Alal hakika ido ginshiki ne na musamman mai jagorantar dan adam ya aiwatar da rayuwa cikin tsanaki. Tsarki ya tabbata ga Allah wanda ya suranta dan adam a bisa tsari mafi dacewa kuma mafi daukaka fiye da sauran halittun dake cikin duniya.

Abubuwan ban al'ajabi game da halittar ido

Allah Mahaliccin sarki ya halitta ido ya tsarashi cikin ban mamaki matuka saboda, cikin yan mintuna biyar kwayar ido takan iya aiwatar da ayyuka aÆ™alla fiye da ayyuka biliyan dubu, kuma inda mutum ya san abubuwan da suke faruwa waÉ—anda suke baiwa idonsa ikon Æ™iftawa, da kuma abubuwan da suke faruwa yayinda yake jujjuya idanunsa wajen kallon abubuwa daban-daban, cikin É—an lokaci Æ™alilan, to da wani zai iya cewa ma a duk halittar da Allah yai a jikin mutum babu abin da ya fi ido ban mamaki. Daga kasa ga bayani game da kariya ta musamman da aka samarwa idon dan Adam. 

Gashin ido: Shin ko mutum ya taɓa tunanin ni'imar dake tattare da gashin ido? ƙaddara ace an bar gashin ido yana toho kamar gashin kai, ace babu wani tsari da mahaliccin ido ya halitta wanda zai hana gashin ido ci-gaba da toho, to yaya mutum yake zaton zai tsinci kansa? Kafin ma ayi batun kariya da gashin idon yake baiwa idanu daga faɗawar abubuwa cikin ido irin su gashi ko ƙura ko kuma ɓurɓushin wani abu.

Idan akai nazari tun daga gashin ido zuwa fatar ido zuwa ƙwayar ido da abuwan dake cikin idon waɗanda suka haɗu suka haifar da gani, abubuwa ne na ban al'ajabi suke faruwa ba tare da mutum ya sani ba.

Fatar ido: Haka idan muka je ga fatar ido, mutane sukan ƙifta idonsu sau dubban lokaci a rana ba tare da sani ba. To wannan fata ta saman ido ita ce mataki na biyu na kariya ga ido wajen hana shigar wani datti ko burbuɗin wani abu.

Sannan kuma akwai wasu sinadarai na musamman da akoda yaushe suke tabbatar da cewa cikin fatar bai rabu da danshi ba, don haka a duk lokacin da mutum ya kifta idonsa to kamar yana goge idon ne. Kamar dai yadda magogin gilashin dake gaban direban mota yake aikin wanke gilashi idan ana ruwa ko kuma domin goge datti.

Da ace fatar ido ba tai dai-dai da ƙwayar ido ba, to da wataƙila ba za ta iya goge idon gaba ɗaya ba, kuma da ba zai taɓa yiwuwa mutum ya goge dattin da ya tattaru a cikin idonuwansa gaba ɗaya ba.

To kuma a ƙaddara ma fatar ba da kanta take wannan aiki ba, sai datti ya taru sannan mutum zai farga ya goge ko kuma ace babu fatar idon duk abin da ya taho haka zai faɗa kaitsaye, babu shakka da rayuwa ta yi wahala ƙwarai, amma mutane da dama ba su damu da tunanin wannan ni'ima ba.

Hawaye: Haka zalika hawaye na da matuƙar muhimmanci ba wai lallai sai na kuka ba, shi ya sa idan wani abu yai wuf ya faɗa ido kaitsaye, nan da nan sai hawaye su zubo dai-dai gwargwado yadda za su taimaka wajen kore wannan datti da ya faɗa cikin ido. Kuma hawaye suna kare ido daga kamuwa da cututtuka, hasalima wannan ɗanɗanon gishiri-gishirin da ake ji a cikin hawaye to wani sinadari ne mai kashe ƙwayoyin cuta na cikin ido wanda ƙarfinsa ya fi na sinadarin kashe kwayoyin cuta irin wanda ake amfani da shi a banɗaki, amma sai mahaliccin ido ya daidaita shi yadda zai yi daidai da ido batare da ya cutar da shi ba.

Kwantsa: Wannan wani sinadari ne mai kauri galibi yana taruwa ne yayinda muke barci, shi wannan sinadari na kwantsa yana taruwa ne sakamakon wata karkuwa ta musamman da aka samarwa ido, yayinda da mutum yake farke yana yawan kiftawa yana kore duk wani datti daya kawowa ido hari shi yasa kiftawar take hana kwantsa taruwa amma da zarar idanuwa sun daina kifta yayin barci to sai kwantsa ta sami damar bubbugowa, wannan sinadari yana taka muhimmiyar rawa wajen tunkudo datti ku kura daga kwayar ido. Duk da yake ba a son yawaitar wannan ruwa, saboda idan yayi to alamu ne na rashin lafiyar ido. Sannan kuma wani abin dubawa a nan shine sai aka kaddara fitar kwantsa yayin barci, in da ace a farke kwantsa ke fita to da idanuwa bazasu taba kasancewa a tsaftace ba.

To idan muka yi nazarin yadda aka tsara gani ya tabbata, za mu ga cewa, tun É—an Adam yana cikin mahaifa, mahaliccinsa ya tsara masa yadda tsarin ganinsa zai kasance.

Kuma an tsara gani akan yadda ƙwaƙwalwa zata iya ajiye abin da mutum ya gan shi ya kuma san shi. Misali abubuwan da mukan iya tunawa a rayuwarmu kamar su yarintarmu, makarantun da muka taɓa yi, gidajen da muka sani, muna gane su ne ta hanyar ganinsu da muka taɓa yi da kuma zama da suka yi a wani ɗan ƙanƙanin bigire a ƙwaƙwalwarmu.

Gane rahamar wannan ni'ima zai yiwu ne kawai idan mutum yai tunanin cewa, yanzu ace duk abin da mutum ya taɓa gani komai sanin da kai masa, sai ace kuma idan ka ɗauki wani lokaci shike nan ka manta shi, kuma ko da ka sake ganinsa ba za ka iya tuna cewa ka sanshi ba, to ai da rayuwa ta shiga ruɗu ƙwarai.

Yanzu bari muyi nazari game da yadda kwayar ido ke aiwatar da aikinta mai cike da ban al'ajabi.

Domin gudanar da wannan nazariyya cikin salo da kuma yadda za a fahimci abin cikin sauki za muyi amfani da kyamara, saboda ita kyamara da kake gani bature yayi satar fasaha ne na halittar kwayar ido ya kerata.

Da farko dai mun san kyamara kuma mun san amfaninta wata kila an taba daukarka hoto ko bidiyo da ita, idan ma baka taba daukar hoto ba lallai ka taba ganin hoto ko bidiyo wanda aka dauka da kyamara, wannan ba shakka acikin haka. 

Ga bayanan yadda kyamara ke aiki dalla-dalla. 

Ta yaya kyamara ke aiki? 

Mu kaddara yanzu ga wata Filawa kyakkyawa tana sheki a cikin hasken rana sai mukayi sha'awar daukar hotonta, gashi mun tanaji kyamara mai kyau kamar haka 📷

camera and eyes
Yadda surar da idanuwa ko kyamara ke kaftowa ke kasancewa a juye (upside down)

Kasani cewa kyamara zata iya aiki ne kadai yayinda haske ya ratsa ta cikin kwayar lens zuwa bayan kyamarar. Yayin da ka saita filawar dake cikin hasken rana da nufin daukar hotonta, hasken dake jikin filawar zai kunduma zuwa cikin kyamara ta mahangar lens, shi kuma lens nan take zai aika da hasken da ya nado zuwa bayan kyamara. 

Kasani cewa haske baya lankwashewa kuma dole sai ya tafi a mike zuwa massarafa. 
Kasancewar kuibin da lens ke karbar haske dan mitsitsi ne idan aka kwatanta da hoton da zai nado. 

Saboda haka hasken da ya nado hoton nan take zai kirkiri wata sabuwar inuwar hoto a kaikaice kuma a juye wato sama a kasa (upside down). Hoton da retina wato zaibar idonka zata kafto shima a juye yake (upside down) to amma sai kwakwalwarka ta fassara hoton sai kaganshi a dai dai. 

Saboda haka da zarar haske ya shiga kyamara sai lens ya kwafi surar abinda za a dauki hotonsa sai ya aika cikin masarrafa daga bayan kyamara, to kaga anan lens yana matsayin retina na kwayar ido kenan. To me zai faru? su kananan kyamarori sunada wani sashe na musamman wato sensor mai iya sinsinowa ko zuko haske zuwa kwakwalwar kyamara. 

To daga nan kuma idan sensor ya zuko wani adadi na haske sai ya tunkuda zuwa masarrafai su kuma nan take sai su kirkiri hoton filawar da muke daukar hotonta. 




Hoton yana samuwa ne yayinda masarrafa ta kirkiri wasu abubuwa yan mitsi-mitsi masu suna pixels. Wadannan pixels din sune suke shata fasalin hoton da ake dauka wanda idanuwa zasu gani a matsayin hoto. 

Misali: Idan ka sami yashi da suminti ka kwaba zaka iya fitar da siffar bulo, kaga anan abubuwan da suka hadu suka gina bulo to sune misalin pixels din da muke magana yayinda suka taru suka shata fasalin hoto acikin kyamara. Pixels din yan kanana fiye da miliyan sai su taru a sami surar ta bayyana yadda idanuwa zasu iya tsinkaya. 

Yadda ido ke gani

Dubi hoton dake kasa kaga yadda aka samu kamanceceniya tsakanin kyamara da ido

To kamar yadda kyamara ke aiki haka idanuwanka ke aiki, yayinda da haske ya shiga ta cornea na ido. Cornea wani sashe ne a gefen  kwayar idonka dan siriri mai daidaita tafiyar haske cikin wasu masarrafai masu suna pupil da iris. Su kuma wadannan masarrafai sune suke aiki kafada da kafada wajen tantance adadin hasken da idanuwa suke karba. 

Iris shine bangaren fari dake jikin kwayar ido, pupil kuma shine bangaren baki na tsakiyar kwayar ido. 


Watakila ko ka taba lura wani lokaci zakaga sashen baki na kwayar idonka ya kara fadi wani lokaci kuma ya tsuke hakan yana da nasaba ne da yadda pupil da iris suke sarrafa adadin hasken da zai shiga kwayar ido. Yayin da pupil ya fadada sai kuma iris ya tsuke don baiwa haske damar shiga pupil idan bukatar hakan ta taso. Haka a cikin kyamara akwai abubuwa masu sarrafa shigar haske cikinta kamar dai yadda na idanuwa suke. 

Dan haka da zarar haske ya shiga pupil yakan biyo ta kafar lens din ido kamar yadda kyamara take, kasancewar lens shine yake laso siffar hoto sai ya tunkuda hasken hoton zuwa masarrafa daga bayan ido. Shi kuma can cikin bayan ido ana kiransa retina wannan sashe yana da wasu sensors guda biyu wadanda ake kira cones da rod. 


Wadannan masarrafai cones da rod sune ke da alhakin tantance launi, wato sune suke iya baiwa ido damar banbance launin abinda ya tsinkaya shin abinda ido ya gani fari ne, baki ne, shudi ne, ja ne nan take zasu tantance. 

Da zarar cones da rod sun karbi hasken da retina ta laso nan take sai su gurza bayanan hasken sai ya rikide ya koma maganadisun lantarki wato electric information. To daga nan kuma sai su aika dashi zuwa jijiyar dake isar da sako zuwa kwakwalwa wato optic nerve.  Wannan siririyar jijiya tana iya daukar sakon maganadisun lantarki zuwa wani gurbi a kwakwalwa mai suna visual cortex ko vision center. Wannan shine cibiyar dake iya karbar abinda ido ya gani sai kwakwalwa ta fassara abin. 

nerves
Jijiyoyi daga ido wadanda suke kai sako zuwa occipital cortex na kwakwalwa.

Wannan sashe na vision center ya kasance daga bayan kwakwalwa ana kiran gurbin occipital cortex ko kuma lobe shine ke da alhakin fayyace sakon makamashin lantarki wanda retina ta aiko, daga nan kuma sai yayi interpreting din sakon daga hoton makamashin lantarki zuwa maganadisun gani. 

Yadda jijiyoyin cones da rod ke tantance launi 

Idan baka manta ba daga sama mun ambaci cones da rods a matsayin sune sanso (sensors) masu alhakin fayyace launin abinda ido ya gani. Wadannan jijiyoyi suna daga bayan retina wato jijiyar dake iya karbar abinda lens ya laso ita kuma sai ta tura zuwa kwakwalwa. Yanzu bari mu koma kan bayanin cones da rods. 

Rods: Wannan jijiya tana aiki ne da haske mafi karanci wato ba sai da haske mai yawa ba take iya tantance abu, da ita muke iya ganin abu da dare saboda haske kalilan ya wadatar da ita. Rods ita take taka rawar gani wajen ganin abu mara launi shi yasa a duhun dare muke iya ganin komai ya zama mara kala (grey) sakamakon karancin haske wanda bazai iya  gamsar da jijiyar cones ba sai dai rods kadai. Kwayar idon mutum tana dauke da kwayoyin halittar rod (rod cells) sama da miliyan 100.

Cones: Amma ita kuma jijiyar cones tana bukatar haske da yawa wanda zai bata damar fayyace kaloli. Muna da ire-iren cones guda uku sune; shudi, kore da ja. A idon mutum akwai jijiyoyin cones kusan miliyan 6 mafi yawa suna nan acikin wata kafa mai suna fovea (wata yar mitsitsiyar kofa ce daga kokowur ido mai taimakawa wajen ganin cikakken surar abu karara).

Yi nazarin hoton dake sama da wanda ke kasa. Zakaga cewa wadannan jijiyoyi masu tantance launi duk suna da wasu fayafayai (disks daga dama) masu kama da hakora, to wadannan disks a cikinsu akwai wasu sinadaran proteins masu zuko haske. Jijiyar rods tana da sinadarin protein mai suna rhodopsin ita kuma cones tana da photopsins. 

Yadda rods da cones ke zuko haske zuwa cikin kayar ido daga bayan retina

Zaman jijiyoyin rods da cones a kokuwar ido daga baya akwai hikima mai girma gaske a bisa dalilai kamar haka:

Abu na farko shine faifan dake kunshe da sinadaran rhodopsin da photopsin suna sauya sinadaran a kowane lokaci yayin da wasu ke bubbugowa sai su maye gurbin na farko haka zasu tabbata suna jujjuyawa (recycling) domin baiwa gabban ido kariya da samun cikakkiyar lafiyar ido.

Abu na biyu shine daga gefen fayafayan nan akwai wasu kwayoyin halitta (epithelial cells (retinal pigmented epithelium: ko kuma RPE a takaice) wannan RPE shine yake sabunta wani bangare na fayafayan rods da cones idan sun tsufa.

Sa'annan kuma wannan cell na RPE yana nadar haske wanda yakan  warwatsu (scattered lights) don ganin abu sosai, wanda hakan yana taimakawa idon karin zunzurutun matakan tsaro na kariya ga lalacewar jijiyoyin rods da cones.

Kamar yadda kake iya GANI shin ko kasan cewa lallai kwakwalwa tana shan aiki sosai kafin gani ya tabbata?. Godiya ga Allah mahaliccin sarki wanda ya wadata mu da wannan baiwa batare da mun biya ko sisin kwabo ba. Allah ka bamu ikon aiwatar da abinda ya dace da wannan ni'ima ta gani daka azurtamu da ita. Allah yasa mu dace.