What does -0.5 mean?

[hornblower]

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My glasses were made in a third world country.

The optometrist (if you can call her that), had me look into a crude machine that took a landscape picture in and out of focus.

Afterward, she had me look through a swatch book of monocles, and asked "Which lens feels easier on your eyes?"

She then wrote down my prescription as "-0.5". What does this mean?

I told her in my country (USA) perfect vision is "20/20". She said she never heard of such a system.

Total charge, $3.

 

[JMU07]

A lot of countries use different numbers than 20/20. Think about it, most places use meters, not feet.

The "crude machine" was an autorefractor. Most docs here have those.

Why did you get your Rx in a developing country?

 

[hornblower]

How bad is -0.5 ? What does an autorefractor diagnose?

Being seen by an optometrist in the USA is very expensive. To make matters worse, I am uninsured.

Since I was already in Tajikistan vacationing, I figured why not get glasses on the cheap.

The eye exam cost me $3 and the glasses $18, for a total cost of $21.

 

[JMU07]

-0.50 is almost nothing, it's very weak and most people don't even wear a prescription for that.

An autorefractor just looks at your eyes while you're watching that picture and spits out an estimated prescription for your eyes. The doc normally uses that as a starting point for their refraction. They're not accurate enough to be used as a final Rx.

 

[Commando303]

Great advice, telling the original poster to get his exam in North America, as if it's now confirmed no other place on earth prescribes an adequate set of eyewear...

As has been said, -.5 refers to the power of the lens. It implies you are very slightly nearsighted (it's difficult for you to focus on things that are far away); this is known as myopia. At this level, your vision is really not too bad, and you might be all right without eyeglasses. I will agree, you ought to go in for a more thorough eye examination, given at a place set up to deliver one.

"20/20" isn't really a measure of visual acuity; it's just a common way in which people describe how well they can see relative to others. Specifically, 20/20 vision means what a "normal" person (i.e., one who does not require vision correction) will see clearly from a distance of 20 feet, you will, too; 20/50, then, indicates what the normal person sees clearly from a distance of 50 feet, you will see well if you are 20 feet from it (i.e., you have to be closer than the other person).

 

[hornblower]

What is the American equivalent of -0.5 ?

 

[JMU07]

What is the American equivalent of -0.5 ?

I'm assuming your doc means -0.50 diopters, this is what we use in America.

 

[hornblower]

I hardly wear my glasses, the reason being, I am concerned my vision will become worse as my eyes become accustomed to the prescription, similar to how someone taking medication needs an increasingly large dose as their body builds tolerance.

Am I right?

 

[KHE]

I hardly wear my glasses, the reason being, I am concerned my vision will become worse as my eyes become accustomed to the prescription, similar to how someone taking medication needs an increasingly large dose as their body builds tolerance.

Am I right?

In 99% of cases, the answer is no. Your prescription will either change or not change whether you wear the glasses or not.

What you describe is a common phenomenon though. At least once a day in my office I see a patient who comes up annoyed at me and claiming that I "ruined their eyes" because now they have to wear those glasses I gave them last year all the time and they can't see anything without them.

But when you test them, the prescription is exactly the same. They just get used to seeing well and then when they do NOT wear the glasses, they realize how crappy they see.

I would be more concerned about using a pair of glasses that is seemingly gleaned largely from an autorefractor than I would anything else. That might be worth a second opinion on.

 

[Commando303]

What is the American equivalent of -0.5 ?

I'm not sure I understand your question. In America, a prescription for eyeglasses can read, "-.5." If you mean, "What's '-.5' in terms of '20/20'?" there's no equation by which to perform a conversion; a very rough statement might be made if your prescription is for -.5 diopter, your vision is 20/40, but, again, this claim is so shaky likely no optometrist would stand by it.

As for whether you do or don't wear your eyeglasses, I'd say, do what feels comfortable: If they help you see better, and you like the result, wear them; if the difference isn't noticeable, and you feel they're a nuisance, don't. At -.5D, the prescription's not so strong you'd be bumping into buildings or cars with your eyes naked. Either decision can cause discomfort/headaches/etc., and you might have a distinct preference based on a situation, so, really, you have to judge the matter largely yourself.

 

[hornblower]

What tests other than the autorefractor does a US trained optometrist perform?

 

[JMU07]

What tests other than the autorefractor does a US trained optometrist perform?

I'm wondering how long you've lived in the US and why you've never had an eye exam here.

The OD doesn't do the autorefractor, usually a tech does it. Once you start the exam with your doc, he'll perform any number of tests depending on what your problem is and why you're there. Probably most importantly he/she will check the health of your entire eye, which I'm sure your doc didn't do.

 

[hornblower]

I am a WASP, born and raised in the United States. My eyes were never examined, other than reading a chart with the big E from time to time.

A year ago someone waved to me in school, and I stood there frozen, not knowing who it was until they walked up close. At that point I realized maybe I need glasses but couldn't afford the $300 visit. I can't make out faces at a distance, especially in the low light of school hallways. Also, road signs are difficult to read at night until drive up close. Thank goodness for GPS.

 

[Commando303]

I am a WASP, born and raised in the United States. My eyes were never examined, other than reading a chart with the big E from time to time.

A year ago someone waved to me in school, and I stood there frozen, not knowing who it was until they walked up close. At that point I realized maybe I need glasses but couldn't afford the $300 visit. I can't make out faces at a distance, especially in the low light of school hallways. Also, road signs are difficult to read at night until drive up close. Thank goodness for GPS.

I'm not sure how G.P.S. would keep you from plowing into a pedestrian or another vehicle...

 

[KHE]

I am a WASP, born and raised in the United States. My eyes were never examined, other than reading a chart with the big E from time to time.

A year ago someone waved to me in school, and I stood there frozen, not knowing who it was until they walked up close. At that point I realized maybe I need glasses but couldn't afford the $300 visit. I can't make out faces at a distance, especially in the low light of school hallways. Also, road signs are difficult to read at night until drive up close. Thank goodness for GPS.

Well, whatever works man but understand that there are thousands of places in the USA where you can get an eye exam for FAAAR less than $300.

 

[hornblower]

What would you consider a fair price for an eye exam?

 

[JMU07]

An eye exam, NOT a contact lens exam? Between $100-150 (at least where I'm from), more or less depending on where you live.

 

[hornblower]

The closest optometrist to me would be Wal-Mart's vision center. Everything I buy there seems to fall apart within a few months.

Is there optical department any good?

 

[aphistis]

Holy professional advice, Batman. How is this thread still open?

 

[hornblower]

You stalked me all the way over from the dental forum? Get a life!

 

[aphistis]

You stalked me all the way over from the dental forum? Get a life!

Be still, my withering self-esteem. 🙄 Ah, SDN, how I've missed thee.

 

[Commando303]

Hey, I have a question: is this forum intended to provide medical advice (as the original poster is seeking) or to host discussions regarding the profession of medicine (specifically, here, optometry)?

 

[Commando303]

OK... Really, this thread seems simply to be seeking med. advice, and I'd like to know whether it's all right to use this forum for such purpose. (Your post suggests it isn't, but I wonder if a mod. or an admin. could reply.)

 

[aphistis]

OK... Really, this thread seems simply to be seeking med. advice, and I'd like to know whether it's all right to use this forum for such purpose. (Your post suggests it isn't, but I wonder if a mod. or an admin. could reply.)

Yes, this thread is soliciting advice. No, SDN does not allow the boards to be used for that purpose.

 

[blysssful]

I hardly wear my glasses, the reason being, I am concerned my vision will become worse as my eyes become accustomed to the prescription, similar to how someone taking medication needs an increasingly large dose as their body builds tolerance.

Am I right?

Is your vision better through the glasses? If the problem that you initially went to the exam for is fixed, what are you complaining about? If your vision and the health of eyes are only worth $21 to you, then you'll get what you paid for.

As was stated earlier, this isn't the place for medical advice. Save your money for a comprehensive eye exam to get your questions answered by someone who can properly evaluate the situation.

And by the way, if you're a healthy young person, you should probably be able to see better than "20/20".

 

[TenaciousGirl]

You stalked me all the way over from the dental forum? Get a life!

A lot of people from various areas read stuff in different forums ... it doesn't necessarily mean someone is stalkworthy.

 

[jc812]

A year ago someone waved to me in school, and I stood there frozen, not knowing who it was until they walked up close. At that point I realized maybe I need glasses but couldn't afford the $300 visit.

How come I am the only one that sees that this is not a -0.50D Rx. if you cannot see someone until they walk up close?
I do not understand why you went to get a $3 exam in a third world country and come here to a forum for US educated ODs for advice. Go get an eye exam and all your questions will be answered. BTW, I have not had an eye exam that cost $300. Maybe glasses, but the visit itself is not $300...

 

[blysssful]

How come I am the only one that sees that this is not a -0.50D Rx. if you cannot see someone until they walk up close?
I do not understand why you went to get a $3 exam in a third world country and come here to a forum for US educated ODs for advice. Go get an eye exam and all your questions will be answered. BTW, I have not had an eye exam that cost $300. Maybe glasses, but the visit itself is not $300...

I understood "close" as a relative term.... as in closer than the OP thought they should have been, but not necessarily smacked up against his or her face.

 

[Commando303]

Wow: the O.P. has been "banned for trolling"?

 

[JMU07]

His post history is full of stuff about being a lower caste Indian and how he'll be disrepected in pharm school. 😕