Is an 8.3 BC significantly different from an 8.4 BC for contact lenses?

Answer 1

Well in soft contact lenses 0.1 change in a base curve USUALLY doesn't make much of a difference. Soft contact lens brands usually only make a few different base curves... for example :8.3 (steep), 8.6(mediuim), 8.9(flat). Most companies make a few different sizes to cater to the different cornea curvatures. If you think about it if 0.1 was a very signifcant diffence then wouldn't all contact lens companies make every base curve increment?? With rigid gas permeable contact lenses 0.1 would make a significant difference but no so much with soft lenses.
With soft lenses a contact lens fitter will choose the closest Base Curve to the cornea curvature of the patients eye first and work from there. All contact lenses fit differently and each fit needs to be examined by an eye care professional to ensure proper fit! :)

Hope that helps a bit :)

Answer 2

When you get an Rx for your eyes. And you decide to get a contact lens, a measurement is made of how round (not from the front) from the side your cornea is. Then, they put on a lens that fits this same curve.

That's called the base curve. But when they put that first lens on, it doesn't always 'fit', as if it fits too well or it's too steep compaired to the curve of the cornea, then it won't move, it'll get stuck., it'll suck itself onto the corneal surface which leads to......pain...etc.

So then, they'll pick a lens with a BC that's NOT as steep, doesn't suck itself onto the cornea, and the flatter one, will hopefully move a little more and allow tear movement, oxygenation and all that stuff to occur. If it's too loose, or too flat, then it'll move all over the place, get lost up there or over there or ....

So the difference between 8.3 and 8.4 will depend on the type of lens, how rigid it is or how soft it is or ????.

To get this 'right'...I'd suggest an Optometrist, not an ophthalmologist, unless the ophthalmologist is one that does this all the time. So you want someone who'll take the time to make sure this is right. The optometrists are really good at refractive stuff (OPTO- eye METRY measure), and the ophthalmologists are better at disease stuff and surgeries and bad eye problems.

Answer 3

no, it is just slightly different base curve, but when you are talking tolerances of the eye, even a little difference makes a difference in comfort, vision, etc.

Answer 4

for the eyes, a 0.1 change is very significant.

Answer 5

For the eye, 0.1 is very significant