8 Tauira o ngā Pātai mō ngā Koha Kanohi
1. Ko te ara mārama e whakaatu ana i te hanganga o te ahua e te karu o te kanohi o te tangata e mate ana i te whatu poto e whakaaturia ana i roto i te ahua...
Kōrero
Ko te tirohanga tata, te myopia rānei, he mate tirohanga o te kanohi e kore ai e taea e te kanohi te kite mārama i ngā mea tawhiti. Ko te pūwāhi tawhiti te tawhiti rawa atu ka taea e te kanohi noa te kite mārama. Ko te tangata noa he kanohi noa tōna pūwāhi tawhiti mutunga kore.
Ko te take o te tirohanga tata ko te pūnaha kōpiko o te kornea-arotahi (he roa rawa te wāhanga whakapae o te karu kanohi) ā, ka whakaitihia te roa o te arotahi o te pūnaha kornea-arotahi, ka arotahihia ngā hihi mārama mai i tētahi pūwāhi tawhiti ki mua i te retina. Kāore ngā hihi mārama mutunga kore e arotahihia ki te retina, ā, kāore e taea e ngā pūtau io i roto i te retina te huri i ngā ngaru mārama hei tohu hiko hei tuku ki te roro.
Ko te whakautu tika ko A.
2. He hyperopia (he hapa kanohi) tō Ani. Nā...
A. Ka neke te pito tawhiti o te kanohi kia tata atu ki te kanohi
B. Ka neke atu te pito tawhiti o te kanohi i te kanohi
C. Ka neke te pito tata o te kanohi ki te kanohi.
D. ka neke atu te pito tata o te kanohi i te kanohi
Kōrero
Ko te tirohanga tawhiti , te hyperopia rānei, he mate tirohanga o te kanohi e kore ai e taea e te kanohi te kite mārama i ngā pūwāhi tata, e ahua pōuri rānei te pūwāhi tata. Ko te pūwāhi tata te tawhiti tata rawa atu ka taea e te kanohi noa te kite mārama. Ko te pūwāhi tata o te tangata noa he 25 cm te whānui. Ka taea e te hunga whai tirohanga tawhiti te kite mārama i ngā pūwāhi tawhiti, nō reira ka taea te kī i roto i te hyperopia , ka nekehia te pūwāhi tata atu i te kanohi.
Ko te whakautu tika ko D.
3. Tirohia te pikitia!
He aha ngā momo hapa kanohi me ngā mōhiti ka taea te āwhina i te hunga e pāngia ana e ēnei mōhiti?
A. Te tirohanga tawhiti me te karāhe kōpiko
B. Te tirohanga tata me ngā karāhe kōpiko
C. Te tirohanga tata me ngā karāhe kōpiko
D. Te tirohanga tata me ngā karāhe kōpiko
Kōrero
Ko ngā hapa o te kanohi i te pikitia i runga ake nei ko te tirohanga tata te matapōkere rānei, sete whakaaturanga o te hoahoa ara hihi i te ahua kei te taha.
Ko te tirohanga tata he mate tirohanga o te kanohi e ahua pōuri ai ngā mea tawhiti. Ko te pūwāhi tawhiti te tawhiti rawa atu ka taea e te kanohi noa te kite mārama. Ko te tangata noa he kanohi noa, he pūwāhi tawhiti mutunga kore tōna.
Ko te take o te tirohanga tata ko te pūnaha kornea-arotahi piko ake (he roa rawa te wāhanga whakapae o te karu kanohi) ā, ka whakaitihia te roa o te arotahi o te pūnaha kornea-arotahi, ka arotahihia ngā hihi mārama mai i ngā pūwāhi tawhiti ki mua i te retina. Kāore ngā hihi mārama e arotahihia ki te retina, ā, kāore e taea e ngā pūtau io i roto i te retina te whakarerekē i te ahunga o te mārama. 
Ka huri ēnei ngaru mārama hei tohu hiko hei tuku ki te roro.
Ka taea te arotahi tika i ngā hihi mārama ki te retina ina whakatakotoria he karu whāiti ki mua i te kanohi. Ka āwhina te karu whāiti ki te hora i ngā hihi mārama kia taea ai te arotahi tika ki te retina.
Ko te whakautu tika ko B.
4. Ka kitea te hanganga tika o te ahua i roto i ngā hapa kanohi whāiti i roto i te pikitia...
Kōrero
Ko te tirohanga tata, te myopia rānei , he mate tirohanga e kore ai e taea e te kanohi te kite mārama i ngā mea i tawhiti.
Ko te take o te tirohanga tata ko te pūnaha kōpiko o te kornea-arotahi (he roa rawa te wāhanga whakapae o te karu kanohi) ā, ka whakaitihia te roa o te arotahi o te pūnaha kornea-arotahi, ka arotahihia ngā hihi mārama mai i tētahi pūwāhi tawhiti ki mua i te retina. Kāore ngā hihi mārama mutunga kore e arotahihia ki te retina, ā, kāore e taea e ngā pūtau io i roto i te retina te huri i ngā ngaru mārama hei tohu hiko hei tuku ki te roro.
Ko te whakautu tika ko A.
5. Mena he hapa kanohi tō te tangata, ā, ko te tawhiti tata ki te pānui he 50 cm, ā, e hiahia ana ia ki te pānui i te tawhiti pānui noa (25 cm), me whakamahi e ia ngā mōhiti he kaha arotahi….
A. ½ dioptā
B. ¾ diopters
C. 1 ½ diopters
D. 2 ngā dioptera
Kōrero
He tirohanga tawhiti te tangata nā te mea ko te pūwāhi tata o tōna kanohi he 50 cm. Ko te pūwāhi tata o te kanohi noa he 25 cm. Ka whakatikatikaina te tirohanga tawhiti mā te whakamahi i ngā karāhe kōpikopiko. He roa arotahi pai ngā karāhe kōpikopiko. Ahakoa kei tētahi tawhiti motuhake ngā mōhiti mai i te kanohi, kāore tēnei e arohia i roto i tēnei tataunga.
E mōhiotia ana:
Te wāhi tata o te kanohi e pāngia ana e te hapa = te tawhiti o te ahua (s') = -50 cm
Me noho te ahua ki mua i te karāhe kōpikopiko kia kitea ai. Nā te mea kei mua te ahua i te karāhe kōpikopiko, he mariko te ahua, ā, he tohu kino tōna.
Te tawhiti pānui noa = te tawhiti o te mea (s) = 25 cm
I pātaihia: Te kaha o ngā karaihe mōhiti
Whakautu:
Te roa o te arotahi o te karu arotahi (f):
1/h = 1/h + 1/h'
1/f = 1/25 – 1/50 = 2/50 – 1/50
1/f = 1/50
f = 50 henemita
f = 0,5 mita = 5/10 mita = 1/2 mita
He pai te roa arotahi o te karāhe arotahi pūkohu nā te mea ka tika ngā hihi mārama mā te pūwāhi arotahi o te karāhe arotahi.
Te kaha o te karāhe kōpikopiko (P) o ngā mōhiti:
P = 1 /f = 1 : f
P = 1 : 1/2
P = 1 x 2/1
P = 2/1
P = 2 diopters
Ko te kaha o te karāhe kōpuku o ngā mōhiti he 2 diopters.
He pai te mana o te karāhe kōpikopiko o ngā mōhiti nā te mea he pai te roa arotahi o te karāhe kōpikopiko.
Ko te whakautu tika ko D.
6. Ka taea e te tangata he hyperopia te pānui pukapuka i te tawhiti o te 125 cm. Hei taea te pānui i te tawhiti noa o te 25 cm, me mau e ia he mōhiti he kaha te karāhe o….
A. 3 1/5 diopters
B. 2 ½ diopters
C. 1 3/5 diopters
D. 1 ¼ diopters
Kōrero
He tirohanga tawhiti te tangata nā te mea ko te pūwāhi tata o tōna kanohi he 125 cm. Ko te pūwāhi tata o te kanohi noa he 25 cm. Ka whakatikatikaina te tirohanga tawhiti mā te whakamahi i ngā karāhe kōpikopiko.
E mōhiotia ana:
Te wāhi tata o te kanohi e pāngia ana e te hapa = te tawhiti o te ahua (s') = -125 cm
Me noho te ahua ki mua i te karāhe kōpikopiko kia kitea ai. Nā te mea kei mua te ahua i te karāhe kōpikopiko, he mariko te ahua, ā, he tohu kino tōna.
Te tawhiti pānui noa = te tawhiti o te mea (s) = 25 cm
I pātaihia: Te kaha o ngā karaihe mōhiti
Whakautu:
Te roa o te arotahi o te karu arotahi (f):
1/h = 1/h + 1/h'
1/f = 1/25 – 1/125
1/f = 5/125 – 1/125
1/f = 4/125
wh = 125/4
f = 31,25 henemita
f = 0,3125 mita
Te kaha o te karāhe kōpikopiko (P) o ngā mōhiti:
P = 1 /f
P = 1/0,3125
P = 3,2 diopters
P = (3)(2/10) ngā dioptera
P = (3)(1/5) ngā dioptera
Ko te mana o te karāhe kōpuku o ngā mōhiti he 3,2 diopters = 3 1/5 diopters.
Ko te whakautu tika ko A.
7. Ka taea e te tangata te pānui mārama i te tawhiti o te 50 cm. Kia mārama ai tana pānui i te tawhiti o te 30 cm, ko te kaha o ngā karāhe mōhiti e hiahiatia ana ko….
A. 1/3 diopter
B. 2/3 diopters
C. ¾ diopters
D. 4/3 diopters
Kōrero
E mōhiotia ana:
Te wāhi tata o te kanohi e pāngia ana e te hapa = te tawhiti o te ahua (s') = -50 cm
Me noho te ahua ki mua i te karāhe kōpikopiko kia kitea ai. Nā te mea kei mua te ahua i te karāhe kōpikopiko, he mariko te ahua, ā, he tohu kino tōna.
Te tawhiti pānui = te tawhiti o te mea (s) = 30 cm
I pātaihia: Te kaha o ngā karaihe mōhiti
Whakautu:
Te roa o te arotahi o te karu arotahi (f):
1/h = 1/h + 1/h'
1/f = 1/30 – 1/50 = 5/150 – 3/150
1/f = 2/150
wh = 150/2
f = 75 henemita
f = 0,75 mita = 75/100 mita = 3/4 mita
Te kaha o te karāhe kōpikopiko (P) o ngā mōhiti:
P = 1 /f = 1 : f
P = 1 : 3/4
P = 1 x 4/3
P = 4/3 diopters
Ko te kaha o te karāhe kōpuku o ngā mōhiti he 4/3 diopters.
Ko te whakautu tika ko D.
8. Tirohia te pikitia e whai ake nei o te hanganga o te atarangi i roto i te kanohi!
Ko te hapa o te kanohi me ngā karāhe mōhiti e whakamahia ana hei whakarite kia tika te ahua ki te retina ko….
Kōrero
Ngā hapa o te kanohi: te tirohanga tata (myopia )
Ka taea te arotahi tika i ngā hihi mārama ki te retina mēnā ka whakatakotoria he karāhe kōpiko, he karāhe wehewehe rānei ki mua i te kanohi. Ka āwhina te karāhe wehewehe ki te hora i ngā hihi mārama kia taea ai te arotahi tika ki te retina.
Ko te whakautu tika ko C.
Pūtake pātai:
Ngā Pātai Whakamātautau Pūtaiao ā-Motu mō te Kura Tuarua/Kura Tuarua Ihirama
