Ngā Whatunga Gurumuda
Ko te karāhe whakanui, he karāhe kōpikopiko rānei e whakamahia ana hei āwhina i te kanohi kia kite i tētahi mea e uaua ana ki te mātakitaki tika mā te kanohi. Ka kiia te karāhe whakanui māmā he karāhe whakanui noa iho nā te mea he iti noa iho tōna kaha ki te whakanui i te ahua o tētahi mea. I te akoranga e whai ake nei, ka ako koe mō ngā karāhe whakanui kore-māmā pērā i te karu hiko, me ētahi atu.
Ka taea te whakatikatika i te tirohanga tata o ngā kanohi mā te whakamahi i ngā karāhe mōhiti me ngā karāhe whakapā. Ka whakapirihia ngā karāhe mōhiti ki te karāhe, ko ngā karāhe whakapā ia ka whakapirihia ki te karu kanohi. He tawhiti motuhake tō ngā karāhe mai i te kanohi, ko ngā karāhe whakapā ia ka piri ki te kanohi kia kore ai e arohia te tawhiti i waenganui i te karāhe whakapā me te kanohi.
Ka whakamāramahia tētahi tauira o ngā raruraru e pā ana ki te tangata he tirohanga tata, he tirohanga tawhiti hoki, he aha ngā momo karaihe e whakamahia ana hei whakataurite i te tirohanga o ngā kanohi, he aha te roa arotahi me te kaha o te karaihe. Ka arotahi tēnei ki te whakamahinga o ngā karaihe whakapā hei whakataurite i te tirohanga tata me te tirohanga tawhiti.
Ka taea te whakatikatika i te tirohanga tata mā te whakamahi i ngā karāhe mōhiti me ngā karāhe whakapā . Ka whakapirihia ngā karāhe mōhiti ki te karāhe, ko ngā karāhe whakapā ia ka whakapirihia ki te kanohi. He tawhiti motuhake tō te karāhe mai i te kanohi, ko ngā karāhe whakapā ia ka piri ki te kanohi kia kore ai e arohia te tawhiti i waenga i te karāhe whakapā me te kanohi.
I roto i tēnei tuhinga, ka whakamāramahia ngā tauira o ngā raruraru e pā ana ki te hunga e pāngia ana e te tirohanga tata me te tirohanga tawhiti, te momo karāhe e whakamahia ana hei whakataurite i te tirohanga o te kanohi, me te roa o te arotahi me te kaha o te karāhe. Ka arotahi tēnei ki te whakamahinga o ngā mōhiti hei whakataurite i te tirohanga tata me te tirohanga tawhiti.
Te whakamāramatanga o te kanohi tiro taringa
Ko te tirohanga tata, te hyperopia rānei, he momo rerekētanga o te tirohanga kanohi e kore ai e taea e te kanohi te kite i te pūwāhi tata, e ahua pōuri rānei te pūwāhi tata. Ko te pūwāhi tata o te tangata kanohi noa he 25 cm te whānui.
Te take o te korenga o te tirohanga taringa
I runga i te whakamārama o mua, ka taea te whakatau ko te take o te tirohanga tawhiti ko te kornea me te iti o te piko o te karu o te kanohi,
kia nui ake ai te roa o te arotahi o te pūnaha arotahi kornea-kanohi, ka arotahi ai te hihi mārama mai i te pūwāhi tata ki muri i te retina.
Te whakamāramatanga o te kanohi tiro tawhiti
Ko te tirohanga tata, te hyperopia rānei, he momo rerekētanga o te kanohi e kore ai e kitea mārama te pūwāhi tata, e pōuriuri ana rānei te pūwāhi tata. Ahakoa he uaua ki te tirotiro i te pūwāhi tata, ka taea e te hunga whai tirohanga tata te kite i te pūwāhi tawhiti. Ko te pūwāhi tata te tawhiti tata rawa atu ka kitea e te kanohi noa. Ko te pūwāhi o te kanohi noa toharite he tata ki te 25 cm. Ko te pūwāhi tawhiti rawa atu ka kitea e ngā kanohi noa. Ko te pūwāhi mutunga kore o te tangata kanohi noa toharite. Ko te mutunga kore he kupu e whakamahia ana hei whakaahua i te roa o tētahi mea tino tawhiti.
Tuhinga Ngā taputapu whatu kanohi tangata
Ngā wāhanga o te kanohi
He kiriuhi mārō, mārama te kornea e hipoki ana i te taha mua o te kanohi. Ka hurihia e te kornea te hihi o te mārama e tomo ana ki te kanohi.
Ko te karu te wāhanga mangu o te kanohi. He mangu te karu, nō reira ka mimiti i te nuinga o te mārama. He kōhao te karu e uru ai te mārama ki roto i te kanohi. Ka nui ake te whānui o te karu, ka nui ake te mārama e tomo ana ki te kanohi, ā, ka iti ake te karu, ka iti iho te mārama e tomo ana ki te kanohi.
Ko te āiri te kaiwhakahaere i te rahi o te karu. Ina tino mārama te taiao e karapoti ana i te kanohi, ka whakaitihia e te āiri te āiri. I tetahi atu taha, ina iti ake te mārama o te taiao e karapoti ana i ngā kanohi, ka whakanuia e te āiri te āiri kia nui ai te mārama e uru ana ki te kanohi. Mēnā kua kite koe i te rerekētanga i waenga i te kanohi ngeru i te awatea me te pō, kāti ka mārama ngāwari koe ki te mahi a te āiri.
He iti ake te tawhiti o te mea i te roa arotahi o te karāhe kōpiko (do < f)
I runga i te tatau i te hanganga ahua e te karāhe pūkohu , ka taea te whakatau ko te tawhiti o te mea (do) he iti ake i te roa arotahi (f) o te karāhe pūkohu, ko ngā āhuatanga o te ahua ko:
– Ko te tikanga o te mariko, kāore te hihi o te mārama e tika ana mā roto i te ahua
– Tū tika
– Ko te tawhiti atu o te mea i te karu arotahi kōpikopiko, ko te rahi ake o te ahua
– Ka tawhiti atu te mea i te karāhe kōpikopiko, ka tawhiti atu te ahua i te karāhe kōpikopiko
He tuhinga mō te whārite o ngā karāhe kōpikopiko (pūpū)
I mua i te ako i te whārite o te karāhe kōpikopiko, kia mārama ki ngā ture tohu o te karāhe kōpikopiko i raro nei.
Ngā ture tohu o te arotahi pūkohu
– Te tawhiti o te mea (do)
Ki te tukuna tētahi mea mā roto i tētahi hihi mārama, he pai te tawhiti o te mea.
– Te tawhiti o te ahua (di)
Ki te whiti te hihi mārama i te ahua, he pai te tawhiti o te ahua (ahua tūturu). Ki te kore te hihi mārama e whiti i te ahua, he kino te tawhiti o te ahua (ahua mariko).
He tuhinga mō te hanganga whakaahua mā te arotahi whakapūmau (pūpū)
Hei mārama ki te hanganga o te ahua e te karu arotahi, akohia ngā tauira rapanga me ngā otinga i raro nei. I tēnei wā, e whakaarohia ana kei te tawhiti motuhake te mea mai i te karu arotahi,
kātahi ka tuhia te hanganga o te ahua e te karāhe kōpikopiko, te tawhiti o te ahua mai i te karāhe kōpikopiko, me te whakanui o te ahua e te karāhe kōpikopiko.
Ko te roa o te arotahi o te karu arotahi kōpikopiko he 20 cm. Kei te taha maui o te karu arotahi ngā mea he 10 cm te teitei. Tātaihia te tawhiti o te ahua, te whakanui o te ahua me te teitei o te ahua, mēnā:
He tuhinga mō ngā hoahoa hihi mō ngā karāhe whatuwhatu (whakapūpū)
Mena kei te taha kotahi o te karāhe kōpiko tētahi mea, ka taea e te karāhe kōpiko te hanga i te ahua o taua mea. Mena e mōhiotia ana te tūranga o te mea i te taha kotahi o te karāhe kōpiko, me pēhea te tuhi i te hanganga ahua o taua mea? Me kī kei te taha maui o te karāhe kōpiko tētahi mea, e whakaaturia ana i raro nei.
Rārangi karaka = karāhe kōpikopiko
Rārangi kikorangi = tuaka matua
Pere (kakariki) = mea
F 1 = te roa arotahi 1 me F 2 = te roa arotahi 2