Mit chhunga crystalline lens chungchang hi i zir belh leh ang u.

Kan mit hi camera te tak te ang maia hnathawh dan hi i ngaihtuah ngai em? Camera-a lens awm ang bawkin kan mit chhungah hian lens pawimawh tak leh mak tak mai a awm a. Vawiin hian mit lens chungchang emaw, doctor-te'n an tih angin ``Crystalline Lens'' chungchang kan sawi dawn a ni. Vawiin hian eng nge a nih tak tak, eng nge a tih, eng ang harsatna nge a thlen theih tih leh eng nge tih theih tih te kan sawi dawn a ni.

Mit lens chu eng nge ni? Camera lens ang mai a ni em?

Ni e, kan mit lens hi a takah chuan camera-a lens nen a inang hle. Hmun mawi tak thlalak i la ang tih han ngaihtuah teh. Chutih lai chuan camera lens chuan light chu a khawlkhawm a, film-ah emaw, digital camera-ah chuan a sensor-ah emaw a direct a ni. Chutiang chuan kan mit lens hian hna a thawk a ni.

Hei hi a chiang a, a curved structure a ni . Ball te tak te, transparent tak ang mai a ni. Kan mit chhungah a awm a, tlem a thuk zawk. He lens kal tlanga êng a kal chuan chu lens chuan chu êng chu a hip lut a, a ben a, a nih loh leh hmun khatah a hruai thleng a ni. Hei hi mit hnung lama sensor, kan retina-a light chu a focus dan a ni. Chutah chuan images kan hmu thin.

Mit lens hnathawh ber chu eng nge ni?

A awlsam zawngin, mit lens hna ber chu mit chhunga êng lut chu a hip lut a, a focus a, mit hnung lama light sensitive tissue retina-ah a hruai a ni.

Mahse, chu chu a ni lo. He lens hian theihna mak tak a nei a. Chu chu a pianzia thlak danglam theihna a ni . I hmaah lehkhabu i chhiar a, chutah rang taka tlang pakhat chu i en thut mai ang tih han ngaihtuah teh. Heng pahnih hi chiang taka hmuh theih nan mit lens hian a pianzia a thlak a ngai a ni. He lens hi hnai taka en chuan a thim zual sauh sauh a, hla taka en chuan a thim zual sauh sauh bawk. Chutiang chuan êng lo lut chu `(Retina)` chungah chiang taka tla turin an ruahman a ni. Hei hi focusing kan tih chu a ni .

He lens hian kan mit hmuh tur focusing power 30% vel a pe a ni. A bak 70% chu mit hmun thianghlim, cornea an tih atanga lo chhuak a ni.

Mit chhunga lens hi khawiah nge a awm tak tak?

Darthlalang atanga i mit i en chuan i mit lai takah chuan circle dum te tak te i hmu thei ang, a dik em? Chu chu ``Zirlai'' kan tih chu a ni. A chhehvelah hian rawng hrang hrang a awm a, chu chu ``Iris'' a ni. Chu ``Pupil'' hnung lamah chuan mit lens chu a awm nghal vek .

A awlsam zawngin sawi ila, mitmeng chu mit luhna ang mai a ni. Iris hian mitmeng lian leh te zawka siamin êng lut zat a control a ni. Chu êng chu mitmeng chhungah a kal a, chutah chuan kan thusawitu, mit lens chu a tawk ta a ni. Lens hian chu êng chu a la a, retina lam a pan a ni. Lens hi mit chhunga layer pahnihna atanga hnuhnung ber a ni.

Mit lens-a thil awmte chu engte nge ni? Chu chu eng thil atanga siam nge a nih?

Mit lens hi bag te tak te ang maia lang, elastic membrane in a hual vel a ni. Hei hi lens capsule an ti a. He lens hi a chung leh a hnuaiah, fiber tha tak tak, elastic thread ang chi hmanga innghat a ni. Chungte chu zonules an ti a.

Heng `(Zonules)` te hi `(Ciliary Body)` an tih part nen an inzawm a ni. Hei hi `(Iris)` hnung lama taksa peng (muscular membrane) a ni. `(Ciliary Muscles)` chhunga muscle te hi lens pianzia thlak danglam theitu an ni. Mak tak maiin heng ruhte hi an inzawm khawm chuan chu `(Zonules)` thread te chu a relax ta a ni. Tichuan lens chu a rawn chhuak a, a round ta a ni. Hei hi thil kan en hian kan focus dan a ni. Mechanism complex tak, mahse mawi tak mai, a ni lo maw?

Mit lens hi eng thil atanga siam nge ni?

Mit lens hi protein chi khat bik atanga siam a ni ber . Chungte chu ``Crystallins'' an ti a. Chuvangin ``Crystalline Lens'' tia koh a ni \hin. Dik tak chuan mit lens hi kan taksa chhunga tissue awm zingah protein tamna hmun a ni.

Heng special `(Crystallins)` proteins te hi lens hi a transparency leh focusing power petu an ni . Thil mak tak chu, heng `(Crystallins)` cell te hi an puitlin chuan, chu chu an lo puitlin chuan nucleus emaw, cell organelle dang emaw an nei lo tihna a ni. Puitlin laiin an bo vek. Hei hi lens a fiah chhan dang a ni bawk.

Mahse, nucleus an neih loh avangin heng cell te hian cell thar siam turin an inthen leh thei tawh lo. Chu chu kan taksaa cell dangte angin an insiam thar lo tihna a ni. Heng cell te hi thinghnah ring ang maia inrem a ni a, layer khat chungah layer dang a awm a ni. Kan dam chhung zawng hian he ring pawn lam kil lamah hian cell thar a lo piang chhuak thin. Tichuan cell hlui te chu a laiah an rawn pungkhawm ta a. Hun a kal zel a, a laiah cell hlui te chu an chak lo tan a, an chhe tan bawk.

Mit lens tichhe thei dinhmun tlanglawn tak takte chu engte nge ni?

Kan tar chhoh zel a, leh boruak chhiatna avang te, a bik takin ni chhuahna avang te hian kan mit lens, a bik takin a laiah ``Crystallin'' cell hlui te chu a chhe tan thin.

• Cataracts: Heng cell te hi an chhe tan chuan an transparency a tlahniam a, lens chu a thim a, opaque a lo ni ta a ni . Chuvang chuan kum upa lam nena inzawm cataract kan ti thin.
• Presbyopia: Tin, kan upat deuh deuh chuan mit lens, chu chu a pianzia thlak danglam theihna (flexibility) a tlahniam bawk. Hei hian hnaih taka thil awmte chu chiang taka hmuh a ti harsa hle. Lehkhabu chhiar tur chuan hla deuh deuha i vawn a ngai ang maiin a lang, a ni lawm ni? Chuvang chuan presbyopia kan ti a ni.

Mit lens-ah harsatna a awm chuan eng symptoms nge a lan ang?

Cataract natna lan chhuah dan

Cataracts a lo awm a, chu chu i mit lens a cloudy a nih chuan i mit a fiah lo thei a, a foggy thei bawk.Window bawlhhlawh atanga khawvel i thlir ang maiin a lang thei. Hmun khatah a intan a, a darh fo thin.

Pawn lam atanga entu tan chuan i mit lai takah chuan a dum (black pupil) chu a dum aiin a dum zawkin a lang thei a, a var pawh a ni thei bawk. (A chang chuan genetic disorder vangin nausen te te pawh mitdelna neiin an piang thei a. Chutiang chuan an hriatchhuah thin.)

Presbyopia natna lan chhuah dan

I lens chu a flexible lo va, a focus theihna a hloh chuan, thil hnai taka hmuh a harsa zual sauh sauh a ni . ``Presbyopia`` chu, a awlsam zawngin, kum upat ruala lo awm ``Farsightedness/Hyperopia`` a ni.

• Chhiar tur chuan chanchinbu emaw lehkhabu emaw tlem a hla deuha i vawn a ngai mai thei.
• Chutiang a nih loh chuan hnai taka hnathawh emaw, lehkha chhiar emaw hian i mit chu a hma aia chau leh na zawkin a awm thei .

Mit lens hmanga harsatna awmte chu engtin nge doctor ten an enkawl?

Refractive error tlanglawn tak tak, presbyopia ang chi enkawlna chi hrang hrang a awm.

• Eyeglasses: Hei hi hmanraw hman tlanglawn ber leh awlsam ber a ni.
• Contact Lenses: Chu chu glasses duh lo tan chuan duhthlan tur tha tak a ni.
• Eye drops: Mit drop chi hrang hrang a awm a, presbyopia hi hun eng emaw chen atan a pui thei a ni.
• Vision correction surgery: He dinhmun hi laser ang chi hmangin siamthat theih a ni bawk.

I mit doctor chuan heng duhthlan turte hi a hrilhfiah thei che a, i tana tha ber tur thlang turin a pui thei bawk che a ni. Hun kal zelah i mit a inthlak danglam zel a, i tar chhoh zel chuan enkawlna hrang hrang i hlawkpui thei a ni.

Cataracts enkawl dan tur

Cataract enkawlna tha awmchhun chu operation hi a ni . Hei hi kalphung pangngai tak leh hlawhtling tak a ni. Hetianga tihnaah hian surgeon chuan i mit lens chhum (cloudy lens) chu a la chhuak a, artificial lens (Intraocular Lens, or IOL) hmangin a thlak a ni. He IOL hian chiang takin a hmu leh thei a ni.

A châng chuan mitdel a lo awm hmain natural lens chu lakchhuah a ni a, IOL dahin myopia, hyperopia emaw presbyopia emaw siam ṭhat a ni. Hei hi refractive lens exchange an ti a.

Engtin nge ka contact lens te hi ka enkawl ang?

Kan tar chhoh zel chuan mit lens chak lohna engemaw zat chu kan veng thei lo nain, kan mit enkawl that chuan a kalphung chu kan tikhawtlai thei a, a chhiatna pawh kan ti tlem thei bawk.

• Ni laka invenna: Pawn chhuah dawnin UV laka invenna tha tak nei sunglass vuah thin ang che.
• Environment pollutants pumpelh rawh: Meizial zu leh secondhand smoke nena inhriat loh tur, a bik takin hengte hi mit tan a pawi hle a ni.
• Diabetes control: Zunthlum i vei chuan mitdelna (cataract) vei theihna a tipung a ni. Chuvang chuan i zunthlum hi uluk taka control a pawimawh hle.

A tawp berah chuan thil hriat reng tur (Take-Home Message) .

Kan mit lens hi thil danglam tak a ni a, mit fiah tak hmuh theihna atana pawimawh tak a ni. Hun a kal zel a, he lens chhunga cell te hi an chak lo thei a, an focus theihna pawh an hloh thei bawk. I tar deuh deuh chuan i mit a fiah lo emaw, hnai taka hmuh a harsat emaw pawh a ni thei.

Mit hriselna enfiah fo hian i mit lens dinhmun hriat reng nan a pui thin. Tichuan, buaina a awm chuan i hre thuai thei a, inenkawlna \ha tak i zawng thei a, i mit hmuhna hlu tak chu i humhim thei bawk. Chuvangin, i mit enkawl hi theihnghilh suh!

` Crystalline Lens, Mitdel, Presbyopia, Hmuh theihna, Mit hriselna