Is it better to have an eye prescription that makes you see okay or have one that is stronger but clearer?

Question

I'm asking because I found out that the grade on my left contact lense is -5.00 and the right lense, -5.75. I see so much clearer with my contacts on than my glasses. My glasses, however, aren't as clear (I don't know the grade on them, but I assume they are lower), but I can defintely see fine with them on, meaning I can function through my day with them.

I'm suppose to be getting a new prescription for glasses, and do you think it would be better to ask my eye doctor to keep the same prescription I have for my glasses or should I upgrade my glasses to match the grade of my contacts?

If I stay with the same prescription for my glasses, then wouldn't that be better for my eyes because it means that I'm not constantly moving my prescription higher and higher? Or is it the opposite?

Also, do you think my eyesight is bad or is it average for an 18-year old? I heard from one of my friends that an eye grade of -8.00 was legally blind; is this true?

Thank you so much to all those who answer and take the time to read my really long question. :)

Best answer will go to the person who actually has a valid source and answers all of the questions I've asked. Thanks again. :D

Answer 1

When you get your eye exam, you may need a stronger Rx. Ask the Dr. if there is any difference in glasses vs contact Rx. Be sure and tell him/her that you can see better with the contacts. I don't know if your eyesight is bad for someone your age, as some need glasses and some do not, but there isn't a thing you can do about it. Getting a Rx that fits your eyes is much better as your eyes are not always straining to see, and you are more comfortable being able to see clearly.

Answer 2

Except in very uncommon circumstances there is no benefit from a deliberate under-correction of the Rx.  Up-to-date but not over-the-top is correct.

The contact and glasses Rx follows the change in the eyes, it doesn't cause it.  Rx change is normal up to  the age of 18-23, when it stops, along with general growth, in most people.  

Tell your friend off.

Rx strength is not a factor in being legally blind.

(though its a commonly held error)  The standard only applies to the vision *with* the best optical correction in place.

"If the vision I get without glasses was the best I could get, I would be legally blind"  is a fair statement for someone with an Rx of -8.00, but not  "I'm legally blind."  If that was true, they shouldn't be driving a car.

Optometrist, retired.