How do glasses help us see? - Andrew Bastawrous and Clare Gilbert

Prevodilac: Milenka Okuka Lektor: Mile Živković

Almost 2000 years ago,

Pre skoro 2000 godina,

the Roman philosopher Seneca peered at his book through a glass of water.

rimski filozof Seneka je virio u svoju knjigu kroz čašu vode.

Suddenly, the text below was transformed.

Iznenada se tekst ispod nje transformisao.

The words magically became clear.

Reči su čudnovato postale jasne.

But it wasn't until a millennium later that that same principle

Ali tek će milenijum kasnije taj isti princip

would be used to create the earliest glasses.

biti iskorišćen da bi se napravile prve naočare.

Today, glasses can help millions of people with poor vision

Danas, naočare pomažu milionima ljudi koji slabo vide

due to uncorrected refractive errors.

zbog nekorigovanih refraktivnih mana.

The key to understanding what that means lies with the term refraction,

Ključ za razumevanje ovoga počiva u reči refrakcija,

the ability of a transparent medium, like glass,

tj. sposobnosti prozirnog medijuma, poput stakla,

water,

vode

or the eye to change the direction of light passing through it.

ili oka da promeni smer svetlosti koja prolazi kroz njega.

The eye has two main refractive surfaces:

Oko ima dve osnovne refraktivne površine:

the cornea and the lens.

rožnjaču i sočivo.

Ideally, these surfaces work together

Idealno, ove dve površine uzajamno deluju

to refract light in a way that accurately focuses light onto the retina,

da bi prelomile svetlost tako da bi ona bila precizno usmerena na mrežnjaču,

the layer of light-sensitive tissue at the back of the eye

tj. sloj tkiva osetljivog na svetlost na poleđini oka,

that works with the brain to give rise to vision.

koja u saradnji sa mozgom tvori vid.

But many people develop refractive errors,

Međutim, kod mnogih ljudi nastaju refraktivne mane,

either during childhood as their eyes are growing,

bilo tokom detinjstva dok im se oči razvijaju

or in later life as their eyes age.

ili kasnije u životu kako im oči stare.

Imperfections in the cornea and lens

Nesavršenosti na rožnjači i sočivu

cause refracted light to be focused in front of or behind the retina,

uzrokuju da se prelomljena svetlost fokusira ispred ili iza mrežnjače,

making images appear blurry.

zbog čega slika postaje zamućena.

People with refractive errors can still see color,

Ljudi sa refraktivnim manama i dalje mogu da vide boje,

movement,

pokrete

and light,

i svetlost,

but the details of what they're looking at are out of focus.

ali su detalji koje posmatraju van fokusa.

People experience refractive errors in different ways,

Ljudi refraktivne mane doživljavaju različito

owing to differences in their eyes.

zbog razlika u njihovim očima.

In some, light refracts too much,

Kod nekih se svetlost prelama previše,

and in others, too little.

a kod drugih premalo.

Eyes with a focal point in front of the retina are called myopic,

Oči kod kojih je žiža ispred mrežnjače se nazivaju miopičnim,

or short-sighted.

iliti kratkovidim.

They can see close objects clearly,

Predmete koji su blizu vide jasno,

but those far away are out of focus.

ali oni udaljeni su van fokusa.

But when the focus point is behind the retina,

Međutim kad je žiža iza mrežnjače,

people are hyperopic, or long-sighted.

ljudi su hiperopični ili dalekovidi.

For them, objects close up are unfocused,

Za njih su bliski predmeti van fokusa,

but distant objects are crystal clear.

a udaljeni predmeti su kristalno jasni.

Finally, some people have a cornea with a non-spherical shape

Na kraju, imamo ljude čija rožnjača nije sfernog oblika

that causes astigmatism,

što uzrokuje astigmatizam,

a form of out-of-focus vision that makes all objects seem blurred,

oblik nefokusiranog vida zbog koga se svi predmeti čine zamućenim,

whether close or far.

bili blizu ili daleko.

As we age, our eyes face new challenges.

Kako starimo, naše oči se suočavaju s novim izazovima.

When we're young, the lens of the eye is flexible

Dok smo mladi, očno sočivo je fleksibilno

and can change shape to bring images into focus,

i može da menja oblik kako bi izoštrilo sliku,

something called accommodation.

nešto što se zove akomodacijom.

This keeps objects in focus when we shift our gaze from far to near.

Zahvaljujući tome predmeti ostaju u fokusu kad skrenemo pogled iz daljine u blizinu.

But as we get older, the lens becomes less flexible,

No kako starimo, sočivo postaje manje fleksibilno

and can't change shape when we want to look at near objects.

i ne može da promeni oblik kad želimo da gledamo predmete u blizini.

This is called presbyopia,

Ovo se naziva presbiopijom

and it affects adults starting around the age of 40 years.

i pogađa odrasle, počevši oko 40. godine.

Myopia,

hyperopia,

Miopija,

hiperopija,

astigmatism,

astigmatizam

and presbyopia.

i presbiopija.

Each of these is a refractive error.

Sve su ovo refraktivne mane.

Nowadays we can fix them all with glasses or contact lenses,

Danas možemo da ih ispravimo naočarama ili kontaktnim sočivima,

which work by refocusing light so it strikes the retina precisely.

koja rade tako što nanovo usmeravaju svetlo da bi precizno pogodilo mrežnjaču.

It's even possible to correct vision with surgery

Čak je moguće operacijom ispraviti vid,

using lasers that change the shape of the cornea

upotrebom lasera koji menjaju oblik rožnjače

and alter its refractive properties.

i koriguju njena refraktivna svojstva.

But glasses remain the most popular.

Međutim, naočare ostaju najpopularnije.

By using carefully crafted lenses

Upotrebom pažljivo izrađenih sočiva

to steer light to exactly the right spot on the retina,

koja usmeravaju svetlost tačno u pravu tačku na mrežnjači,

a person's clear vision can be restored.

ljudima može da se vrati jasan vid.

We've come a long way since Seneca's discovery

Prešli smo dug put od Senekinog otkrića

and the crude glasses of yesteryear.

i prostih naočara iz prošlosti.

In 1727, a British optician named Edward Scarlett

Britanski optičar, po imenu Edvard Skarlet, je 1727. godine

developed the modern style of glasses

razvio savremeni stil naočara

which are kept in place with arms which hook over each ear.

koje stoje na mestu uz pomoć ručki koje se kače za uši.

Today's glasses take their inspiration from that design,

Današnje naočare su inspirisane tim dizajnom,

but they're also much more precise and personal.

ali su takođe daleko preciznije i ličnije.

Each pair is tailored for an individual to bring out their unique powers of sight.

Svaki par je skrojen po meri pojedinca kako bi njegova moć vida bila vraćena.

So if you're one of the 500 million people with a problem with close or far vision,

Pa ako ste jedan od 500 miliona ljudi

s problemom kratkovidosti ili dalekovidosti

or both,

ili s oba,

there's a pair of glasses out there waiting to reveal a whole new world

tamo negde postoji par naočara koje čekaju da vam otkriju novi svet

that's hiding in plain view.

koji se skriva vama na očigled.