eye exam vs contact eye exam

[ooscubaoo]

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What's the difference between a regular eye exam and a contact eye exam? I know for a contact eye exam you get fitting for your contacts, but are the exams to see what your prescription exactly the same? If so, how is it possible that my contact presciptions different from my glasses prescription?

 

[Katalio]

I think it has to do with vertex distance..
at a higher power, the distance between your eyes and the contact lens vs your eyes and the lens on your spectacle has a different net power, so you have to calibrate it! =)

(What's what I learn when I took my optician course.. but I dunno for sure ) -=P

Katalio

 

[rpames]

That is basically correct. As the lens is brought closer to the eye, it effectivly gives your eye more MINUS power. That means for myopes the contact needs to be less powerful than the glasses and for hyperopes the contact needs to be more powerful. In reality, you only need to make these adjustments with moderate and high powers. A -0.50 sph would not need to be adjusted.

Since I haven't done a CL exam I will let someone else tell you how they are different.

 

[ooscubaoo]

what should be higher, the contact lenses or the glasses?

Actually i think my glasses and my contact lenses are the same, but my friend said they shouldn't be the same. I'm not sure because i went to the optometrist yesterday asking for a contact lense exam and my optometrist did not have the astigmatism contact so she told me to come back for the fitting. I come back today to tell her i don't want the fitting and i just wanted to update my glasses instead. The thing is I did not have to go through another exam for my glasses. IS that NORMAL? Wouldn't I have to go through another exam just for my glasses? I just dropped off my glasses and did not think about it, but now i think i should worry about it.

 

[rpames]

In a CL exam they do everything that is done during a regular exam PLUS some more tests. Therefore if a CL exam is done, there is no problem in getting just glasses.

As far as which power should be higher...like a stated above, if you have a lower perscripting there may not be a difference in the two perscriptions. But if you have a higher power (like greater than 2.50, someone correct me if I'm way off), than it depends if your are farsighted (plus lenses) or near sighted (minus lenses). For nearsighted, your glasses will be more powerfull (higher). If you are farsighted, your contacts will be more powerfull.

 

[ooscubaoo]

my contacts are -3.00 + 1.5 stigmatism left eye, -3.75 right eye according to the CL exam i took yesterday. She told me my glasses would be -3.00, and 3.75 as well. thing is before my glasses were 0.50 difference from my glasses. so having my contacts and glasses at the same degree is normal? IF anything, i'll just go back and ask my optometrist when I come pick up my glasses next week. if you guys have more info about this, please post.

 

[cpw]

anything under +/- 4.00 you do not have to vertex. It will be the same as your glasses rx.

 

[Xalatan1]

What's the difference between a regular eye exam and a contact eye exam? I know for a contact eye exam you get fitting for your contacts, but are the exams to see what your prescription exactly the same? If so, how is it possible that my contact presciptions different from my glasses prescription?

they should be the exam, with the contact lens exam consisting of more tests