# Need some help deciphering an eyeglasses prescription

**URL:** <https://boards.straightdope.com/t/need-some-help-deciphering-an-eyeglasses-prescription/788242>\
**Category:** Factual Questions\
**Created:** [June 6, 2017, 2:11am UTC](https://boards.straightdope.com/t/need-some-help-deciphering-an-eyeglasses-prescription/788242 "2017-06-06T02:11:27Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\
**Post date:** [June 6, 2017, 2:11am UTC](https://boards.straightdope.com/t/need-some-help-deciphering-an-eyeglasses-prescription/788242/1 "2017-06-06T02:11:27Z")

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I’m trying to help my daughter get some online glasses

[Rx note Pic Here](http://i349.photobucket.com/albums/q383/seamaster100/Resized_20170605_164846%201_zpsv0xwoeih.jpeg)

The online eyeglasses site [www.eyebuydirect.com](http://www.eyebuydirect.com)

Has these categories for eyeglasses Rx input

```
                  Sphere (SPH) Cylinder (CYL) Axis  

```

Right Eye (OD) Sphere = -7.75 Cylinder = -.75 Axis = 160  
Left Eye (OS) Sphere = -8.25 Cylinder = ? Axis = ?

Do I put -.75 and 160 in the left eye sections as well or leave them at 0/blank?

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**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [June 6, 2017, 2:16am UTC](https://boards.straightdope.com/t/need-some-help-deciphering-an-eyeglasses-prescription/788242/2 "2017-06-06T02:16:50Z")

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“Sph” indicates that _only_ a spherical prescription is given for the left eye, i.e. no astigmatism correction.  
So leave them at zero.

see halfway down this page

> **[How To Read Your Eyeglass Prescription](https://www.allaboutvision.com/eyeglasses/eyeglass-prescription.htm)**
>
> Discover why contact lens prescriptions differ from eyeglass prescriptions, and what all those numbers mean.

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**Author:** ![Folly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folly/32/3219_2.png) [@Folly](https://boards.straightdope.com/u/Folly)\
**Post date:** [June 6, 2017, 2:38am UTC](https://boards.straightdope.com/t/need-some-help-deciphering-an-eyeglasses-prescription/788242/3 "2017-06-06T02:38:30Z")

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Did they give you PD, pupillary distance?

You’ll need that too and sometimes they don’t give it to you unless you ask. You can trying measuring it yourself, but you want it to be pretty accurate.

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**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\
**Post date:** [June 6, 2017, 2:53am UTC](https://boards.straightdope.com/t/need-some-help-deciphering-an-eyeglasses-prescription/788242/4 "2017-06-06T02:53:32Z")

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> [@Folly](#):
>
> Did they give you PD, pupillary distance?
> 
> You’ll need that too and sometimes they don’t give it to you unless you ask. You can trying measuring it yourself, but you want it to be pretty accurate.

Yes I measured that for her.

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**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\
**Post date:** [June 6, 2017, 12:41pm UTC](https://boards.straightdope.com/t/need-some-help-deciphering-an-eyeglasses-prescription/788242/5 "2017-06-06T12:41:57Z")

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I’m glad to see you using eyebuydirect.

We tried Zenni a while back and both of us got really crappy glasses.

This round we did eyebuydirect and I am really happy with the result. A bit more than Zenni but we got actually usable glasses! Sturdy, well made and nice looking. Also arrives faster. (From Canada, not China.)