I have a -4.00 for my contacts and my dr. gave me a -4.25 for my glasses. Has anyone else had this kind of difference and if so then why do you think he did this? It honestly seems strong when i wear them now, if it is a normal thing that is done then i won't fuss about it cuz i only wear them at night, but i really like my new glasses and want to wear them more often....or do you think it could be that i rarely wear my glasses so having a pair with the right prescription now is just a little shocking to my brain? I would really appreciate someone's input on this. I would have asked my Dr. this stuff but he was too busy sexually harassing me....yeah, uncomfortable situation so I wasn't in the mood to ask questions and prolong the appointment.

The originator of that type of harrassment has serious credibility issues.
No matter the cost, it would be worth it to get a second opinion.

Yes, it is common to have a lower contact prescription compared to your glasses prescription. The contact prescription is lower because the contact sits right against your eyeballs, but the glasses sit about 1 inch away from your eyeballs. So the prescription for your contacts needs to be adjusted accordingly.

How were you sexually harassed?

Thank you so much for the reply. I never knew that about glasses...probably cuz i never wear them much eh.

In response to how i was harassed. This doctor would crack little witty jokes a lot. And he was really funny and so i laughed. I guess he misinterpreted that. He then would crack a joke and place his hand on my knee, then he would place his hand on my hand...for a time period longer than friendly and he kind of squeezed my hand a couple of those times...then at the end of the visit he actually gave me a hug, he dared to cross that space bubble and give his patient a hug. I don't know what kind of vibes i was sending, but it wasn't intended to say "Hey, i like that, keep going, give me a hug". But i know i should have said something...i just really needed new contacts so i wanted to just finish the visit up. but i probably won't be going there again.
Thanks for the interest in that, i was feeling pretty weird about it, it's nice to talk about to someone who wants to hear.

Thank you so much for the reply. I never knew that about glasses...probably cuz i never wear them much eh.

In response to how i was harassed. This doctor would crack little witty jokes a lot. And he was really funny and so i laughed. I guess he misinterpreted that. He then would crack a joke and place his hand on my knee, then he would place his hand on my hand...for a time period longer than friendly and he kind of squeezed my hand a couple of those times...then at the end of the visit he actually gave me a hug, he dared to cross that space bubble and give his patient a hug. I don't know what kind of vibes i was sending, but it wasn't intended to say "Hey, i like that, keep going, give me a hug". But i know i should have said something...i just really needed new contacts so i wanted to just finish the visit up. but i probably won't be going there again.
Thanks for the interest in that, i was feeling pretty weird about it, it's nice to talk about to someone who wants to hear.

Yeah, you probably shouldn't go back. That seems inappropriate.

Recently, a local opthalmologist was found guilty of sexually assaulting ten of his sedated patients. Some of the patients were eye cancer patients who were heavily sedated when he sexually assaulted them. He lost his license to practice for the rest of his life and has to spend 2 years in prison.

This does not add up. If you say they feel strong, then your contact lense pescription may be too high and you are accomodating the difference. You should be a -3.25 or -3.5 contacts if you are -4.25 glasses. I am supposed to be -5.5(left) and -5(right) but with the -4 contact sample I tried I was seeing just as well as my glasses in either and both eyes! My sister also got overpescribed contacts -2.75 when they should have been -2. Her eyes have since gotten worse in the past 6 months. Its sad how some people get pescribed contacts too strong or glasses too weak. One lady I know wears -3 contacts and -3 glasses and she says things are a little blurry with the -3 glasses. I told her she needs -3.75 glasses

myope33 :

In your last most resent posts,your suggestions seem to reflect a very keen "insight".You must have gained a lot of knowedge from reserching Google,or you may have some advanced training in the eye care field ?

Eyestwo22

I am not a doctor but have worn contacts and so have my friends and family. I have observed the difference in pescription. Like I also said, my -4 contacts correct me as well as -5 glasses. I came to find out that you multiply your glasses pescription by 1.25 to arrive at contacts. This holds true for anyone ive seen that was pescribed correctly.

This does not add up. If you say they feel strong, then your contact lense pescription may be too high and you are accomodating the difference. You should be a -3.25 or -3.5 contacts if you are -4.25 glasses. I am supposed to be -5.5(left) and -5(right) but with the -4 contact sample I tried I was seeing just as well as my glasses in either and both eyes! My sister also got overpescribed contacts -2.75 when they should have been -2. Her eyes have since gotten worse in the past 6 months. Its sad how some people get pescribed contacts too strong or glasses too weak. One lady I know wears -3 contacts and -3 glasses and she says things are a little blurry with the -3 glasses. I told her she needs -3.75 glasses

Are you kidding me? How can you tell somebody over the internet what power contact lenses they should be wearing without examining them?

Are you a doctor? NO

Did you examine the creator of this thread? NO

If this can be done over the internet, then why are optometrists and ophthalmologists going to school for so long?

I came to find out that you multiply your glasses pescription by 1.25 to arrive at contacts. This holds true for anyone ive seen that was pescribed correctly.

What???????

That makes no sense.

My glasses prescription is a -10.00, so if I multiply that by 1.25 for my contact lens prescription, then I should be wearing a -12.50 for my contacts?????

You are completely wrong.

If I was confusing, I apologize. Your -10 glasses would be equal to -8 contacts. 8 times 1.25 is 10. I never said I was a doctor but if someone gives me their glasses or contact pescription, anyone can do the math. Its because of vertex distance, contacts sit directly on the eyeball while glasses hover away from it.

If I was confusing, I apologize. Your -10 glasses would be equal to -8 contacts. 8 times 1.25 is 10. I never said I was a doctor but if someone gives me their glasses or contact pescription, anyone can do the math. Its because of vertex distance, contacts sit directly on the eyeball while glasses hover away from it.

No,No,No.You are correct regarding the effect of vertex distance but totally wrong regarding your 1.25 multiplication factor.Vertex distance starts to become relevant as you go past 4 diopters and becomes increasingly so as the powers increase.

No,No,No.You are correct regarding the effect of vertex distance but totally wrong regarding your 1.25 multiplication factor.Vertex distance starts to become relevant as you go past 4 diopters and becomes increasingly so as the powers increase.

Some would say vertex distance becomes a factor at +/- 3.00 :)

Some would say vertex distance becomes a factor at +/- 3.00 :)


At +/- 3.00,correction for vertex distance is less than .25 D,which is not clinically relevant.

Then howcome me and my friends experience a constant 1.25 factor in vertex distance? The difference in diopters between glasses and contacts go up the more myopic you are but the percentage is fixed. I have tried samples of several different pescriptions and in every case, it was 1.25 times stronger than glasses. Even the weaker samples held true. One of my friends is -2 glasses and -1.75 contacts. I see slightly better with -2.75 contacts than -3.25 glasses but the difference is small though.

Then howcome me and my friends experience a constant 1.25 factor in vertex distance? The difference in diopters between glasses and contacts go up the more myopic you are but the percentage is fixed. I have tried samples of several different pescriptions and in every case, it was 1.25 times stronger than glasses. Even the weaker samples held true. One of my friends is -2 glasses and -1.75 contacts. I see slightly better with -2.75 contacts than -3.25 glasses but the difference is small though.


The percentage is not fixed.Correction at -7.00D is .50D,correction at -10.00D is 1.00D.These corrections dont take into account the effect of the tear film forming a tear lens and the image size difference formed on the retina with cls versus eyeglasses.The most accurate way to refine the cl power is to perform an overrefraction over the cls while looking at the eyechart(at the optometrists office).

You are right that the percentage isnt fixed, but its a good approximation and holds true for me and my friends. Not everyone will get exactly 125% but it should be close to that. A general rule is that your contact pescription should be lower than your glasses pescription if you are more than about -1 diopters. You are correct in saying your tear film affects matters. Those with dry or moist eyes may need different contact pescriptions. Also your vision with contacts fluctuates depending on the dryness of your eyes. I guess this is why sometimes they just pescribe the same power contacts vs. glasses for low pescriptions, especially if your eyes tend to get a little dry. However an overcorrection will make things from near blurry, strain your eyes and speed up myopic progression. Its a tricky subject determining the exact pescription for each person, taking into consideration dryness of eyes and vertex distance.

At +/- 3.00,correction for vertex distance is less than .25 D,which is not clinically relevant.

Really? Mmm, I wonder if a 42 year-old emerging presbyope with a glasses prescription of -3.00 would prefer a contact lens prescription of -2.75 instead of a -3.00?

better yet monovision :) I know what its like to be presbyopic. With strong contacts things from near become blurry. You may want enough undercorrection to see clear from near. My glasses pescription is -5 and I find that I need -2.75 contacts to have any useful ability to see from near. This is about equal to -3.5 glasses as the -2.75 contacts correct me in the distance a tiny bit more than my -3.25 "computer" glasses. Of course I like reading even better with no correction. I dont wear contacts much and if I do I cant have both near and distance vision anyway and im not about to bother putting reading glasses over contacts when I can read without any correction. If you stick to glasses you can take them off for reading or other near work :)


edit: monovision doesnt work for everyone. I dont like it, its disorientating having one eye blurry and the other clear and it hurts my binocular vision. My mom does use monovision to give 20/30 in the dormant eye(best corrected) and 20/100 in the other and she says it does bother her sometimes but better than having to reach for readers all the time. She often sticks to progressive glasses. She could remove her glasses(like -9) to read but having your nose nearly touch the book isnt exactly convinent