# 20/20 vision

#### kuleshov

##### Senior Member
I know that this stands for perfect vision. What if you are myopic?
In Spanish we count dyoptries. We say "Tengo 10 dioptrías", which is a lot.
If you only have "una o dos diptrías" you are not very myopic.
So, what about myopic people? Are they 18/20?

• #### Rebecca Hendry

##### Senior Member
I don't think it is common to talk about anything other than 20/20 vision using numbers, apart from perhaps when you are at the optician.

We talk about being short-sighted (i.e. you can't see things in the ditance) and long-sighted (you can't see things close up).

I am short-sighted, and the strength of the contact lenses I use is -2.75. I think that the long-sighted equivalent would be +2.75.

#### LadyBlakeney

##### Senior Member
This is very interesting, Kuleshov and Rebecca.

So, when you are saying, for instance, that one person is more/less short/long-sighted than other, how do you measure it? Do you do it at all?

Thanks in advance.

#### Luke

##### Member
The numbers are meaningful - it is a measure of what your eye can see at a given distance compared to what a normal eye can see. So if your vision is 20/40, you have to be 20 feet from an object to see it as well as a normal person can from 40 feet. If you have 20/15 vision, then you can see better than normal.

#### Rebecca Hendry

##### Senior Member
Well I would talk about the strength of my glasses or contact lenses, so -2.75.

It's odd, but it's something that I remember talking about frequently in Spain, but in Britain it very rarely seems to crop up in conversation!

#### lauranazario

##### Moderatrix
Rebecca Hendry said:
I don't think it is common to talk about anything other than 20/20 vision using numbers, apart from perhaps when you are at the optician.

We talk about being short-sighted (i.e. you can't see things in the ditance) and long-sighted (you can't see things close up).
Interesting... in the USA we use near-sighted and far-sighted.

Saludos,
LN

#### Gringosimo

##### Senior Member
lauranazario said:
Interesting... in the USA we use near-sighted and far-sighted.

Saludos,
LN

Beat me to it Lauranzario. In the U.S. being short sighted means something all together different. It refers to not considering future consiquences before you make decisions.