How to choose the base arc? How do I calculate my base arc?

The selection rule of the base arc is: it should be loose but not tight. Most of the Chinese eye arcs are in between, but there are a few as high as even, or as low as, even, when the base arc of the lens you choose is quite different from the base arc of your own eyeball, it may produce an uncomfortable feeling of wearing.

The larger the base arc of the soft contact lens, the flatter the inner surface of the lens, if the base arc of the lens is larger than the base arc of the eyeball, the lens may not fit the eyeball and is easy to displace; If the base arc of the lens is smaller than the base arc of the eyeball, it is easy to cause the eye to feel too tight and uncomfortable. Of course, these two values cannot be completely matched. In general, the basal arc of the lens should be greater than 10% of the basal arc of the eye.

The selection rule of the base arc is: it should be loose but not tight. Most of the eye arcs of Chinese people are between the rolling sheds, but there are a few as high as even, or as low as, even, when the base arc of the lens you choose is quite different from the base arc of your eyeball, it may produce an uncomfortable feeling of wearing.

The larger the base arc of the soft contact lens, the flatter the inner surface of the lens, if the base arc of the lens is larger than the base arc of the eyeball, the lens may not fit the eyeball and is easy to displace; If the base arc of the lens is smaller than the base arc of the eye, it is easy to make the eye feel too tight and uncomfortable. Of course, these two values cannot be completely matched. In general, the basal arc of the lens should be greater than 10% of the basal arc of the eye.

First of all, if the base arc is too large, it will cause the contact lenses to shift and slide, and when the base arc of the lens is smaller than the base arc of the eye, it is easy to cause too tight and uncomfortable conditions.

So, what is a base arc?

The base arc (BC), which is the curvature of the lens.

The closer the curvature of the lenses is to the eyeball, the more comfortable it fits.

Most Chinese people's eye arc is in between, so the base arc range of the lens is generally selected.

You can buy a few more contacts with different base arcs, experience, find the most comfortable base arc value for yourself to wear, and finally recommend that fairies wear contact lenses purchased from regular channels, which are beautiful and safe.

There are two methods, one is to go to optometry, and the other is to buy some low-end ** try-on...

If the base arc fits, then wearing contact lenses will not affect the vision at all, and it is easy to put on and take them off when wearing.

If the base arc is large, things that are near will become blurry, and things that are far away will become clearer, and it will be worn several times before being attached.

If the base arc is small, the eyes will feel swollen and uncomfortable, and it will be difficult to pick up.

Divide by the curvature of the cornea to get your basal arc.