svachhamandal

kaurniya
Schematic diagram of the human eye en.svg
maanav aankh ka aarekh (oopari madhya or lebal kiya hua kaurniya)
Gray871.png
maanav kaurniya ka urdhvaadhar sekshan, margin ke nikat se maigneefaaid
1. epitheeliym.
2. aantarik ilaastik falak.
3. sabstainshiya praupriya.
4. prushth ilaastik falak.
5. aantarik kaksh ka endotheliym
a. sabstainshiya praupriya ki aantarik part mein tirchhe reshe.
b. laimile, jiske reshe aar-paar kate hone se dauted dikhte hain.
c. kaurniya ki rakt-kanikaaen jo anubhaag mein fyoojeefaurm prateet hoti hain.
d. laimile, jiske reshe lambavat kate hote hain.
e. sklera mein parivartan, jisk faayabrileshan bhinn hai aur moti epeetheeliym se aavrutt hai.
f. kaurniya ke kinaare kati hue kshudr rakt-vaahikaaen
gre ki sharee‍aariki subject #225 1006

svachhamandal ya kaneeniya (angreji:kaurniya) aankhon ka vah paaradarshi bhaag hota hai jis par baahar ka prakaash padta hai aur usaka pratyaavartan hota hai. yeh aankh ka lagbhag do-tihaai bhaag hota hai, jismein baahari aankh ka rangeen bhaag, putali aur leins ka prakaash dene wala hissa hote hain. kaurniya mein koi rakt vaahika naheen hoti balki ismein tantrikaaon ka ek jaal hota hai. isko poshan dene vaale dravya vahi hote hain, jo aansoo aur aankh ke anya paaradarshi drav ka nirmaan karte hain.[1] praay: kaurniya ki tulana leins se ki jaati hai, kintu inmein leins se kaafi antar hota hai. ek leins keval prakaash ko apne par girne ke baad failaane ya sikodne ka kaam karta hai jabki kaurniya ka kaarya isse kaheen vyaapak hota hai. kaurniya vaastav mein prakaash ko netragolak (aankh ki putali) mein pravesh deta hai. iska uttal bhaag is prakaash ko aage putali aur leins mein bhejata hai. is tarah yeh drushti mein atyant sahaayak hota hai. kaurniya ka gunbadaakaar roop hi yeh tay karta hai ki kisi vyakti ki aankh mein dooradrushti dosh hai ya nikat drushti dosh. dekhne ke samay baahari leinson ka prayog binb ko aankh ke leins par kendrit karna hota hai. isse kaurniya mein badlaav aa sakta hai. aise mein kaurniya ke paas ek krutrim contact leins sthaapit kar iski motaai ko badhaakar ek naya kendra bindu (fokal point) bana diya jaata hai. kuchh aadhunik contact leins kaurniya ko dobaara iske vaastavik aakaar mein laane ke liye dabaav ka prayog karte hain. yeh prakriya tab tak chalti hai, jab tak aspashtata naheen jaati.

dosh va daan

kaurniya camere ki lains ki tarah hota hai jisse prakaash andar jaakar reteena par padta hai iske baad chitr banta hai, jise drushti-dhamani (optik narv) vidyut sanket roop mein mastishk ke upayukt bhaag tak pahuncha deti hai. kaurniya kharaab hone par reteena par chitr naheen banta aur vyakti andha ho jaata hai.[2] kai baar aankhon mein sankraman, chot ya vitaamin A ki kami ke kaaran bhi kaurniya kharaab ho jaate hain. kaurniya mein dosh aane par usaka upachaar shalya-kriya dvaara kiya jaata hai. ye operation saralata se ho jaata hai. ismein shalya-chikitsak kaurniya se judi tantrikaaon ko achetan kar bina rakt bahaae is kriya ko poorn kar dete hain.[1] kabhi-kabhi operation ke dauraan kaurniya par kisi baahari vastu se kharonch bhi lag jaati hai ya fir palak ka hi koi baal tootakar is par kharonch bana deta hai. is sthiti mein kuchh aankh ki taral davaaiyon (aaidraup) se kaurniya kuchh hi dinon mein theek ho jaata hai. bahut se log apna kaurniya daan kar dete hain taaki koi unki aankhon se yeh duniya dekh sake. is kaurniya daan ko hi asal mein netr daan kaha jaata hai. netradaan karne vaale vyakti ki mrutyu ke baad uske kaurniya ko nikaalkar machine (MK meediym) ki sahaayata se usaki koshika ghanatv (sales densiti) dekhi jaati hai. ek varg mileemeetar ke kshetr mein teen hajaar se adhik koshikaaen hona achhe kaurniya ki pehchaan hai.

pratyaaropan

kaurniya, iris aur lens ki slit laimp chhavi.

kaurniya ke operation ka prachalit sabse pehle Italy mein viksit kiya gaya tha. iske baad use America mein bhi apnaaya gaya aur baad mein vishv bhar mein apnaaya gaya hai. is operation mein rogi ke ek daaaint aur uske paas ki kuchh haddi ko nikaal kar taraasha gaya aur us mein belanaakaar leins ko baithaane ke liye ek chhed kiya gaya. leins sahit daaaint ko pehle rogi ke gaalon ya kandhon ki tvacha ke neeche do maheenon ke liye pratiropit kiya jaata hai, taaki ve achhi tarah aapas mein jud jaaeain. baad mein unhein vahaaain se nikaal kar aaainkh mein pratiropit kiya jaata hai. iske liye aaainkh vaale gaddhe ko pehle achhi tarah taiyaar kiya jaata hai. aaainkh ki shleshma waali parat mein ek chhed kiya jaata hai, taaki leins thoda-sa baahar nikla rahe aur aaspaas ke prakaash ko grahan kar sake.[3]

haal ke varshon mein ek naya vikalp intraastromal kaurniyl ring ko plastic se vishisht roop se is tarah banaaya jaata hai ki ye kaurniya ke andar baithaaya ja sake. inke design kuchh is tarah se bane hote hainki ye kaurniya ko dobaara se khoi hui aakruti vaapas lautaate hain aur drushti sudhaarate hain. is pratyaaropan mein kaurniyl ootak ko nikaalne ki aavashyakta naheen padti hai. ismein rogi ko theek hone mein bhi adhik samay bhi naheen lagta hai. ye naya kaurniya pratyaaropan ek shalyarahit prakriya hai jismein kaurniya ke disk ko hataakar daan kiye gaye ootak ko lagaaya jaata hai. haalaanki ye safalataapoorvak ho jaata hai lekin ye bahut hi aaraamadaayak hota hai aur theek hone mein bahut samay lagta hai.[4]

sandarbh

  1. a aa kaurniya|Hindustan live. 8 June 2010
  2. aankh chaahane vaalon ki prateeksha soochi teen saal tak pahunch gayi. growth India. 17 July 2009.
  3. daaaint lagte hi laut I drushti . web duniya. Ram Yadav
  4. aankhon ke liye khatra hai keraatokonas. deshabandhu.com. 15 June 2009. dau॰ mahipaal S.sachadev, Chairman, Safdarjung enkalev center for site