Contact Lens Fitting
Because contact lenses are in direct contact with the eye, they need to be fitted to the shape of the eye. Many factors can affect the type of lens you need to be fitted for, including purpose, Astigmatism, some colour, and other eye issues.
You cannot use your regular eyeglasses prescription to get contact lenses. To wear contact lenses, there are other special measurements that need to be taken. Like clothing and shoes, contact lenses are not 'one size fits all'. Also, size can vary depending on the manufacturer of the lenses.
You can wear contacts for many vision correction problems, even if you have had refractive surgery. Because the contour of the eye has been altered, the contact lens will need to be fitted again and may require a more specialized lens than normal.
Coloured contact lenses are fitted like normal lenses. Because of this, it may be possible to see some of the colour of the lens overlapping the pupil. This can be a problem for lens wearers who want opaque lenses. Because opaque lenses have a solid colouring to completely change the eye colour of the wearer, vision can be affected and limited when the pupil becomes larger, such as in dimly lit environments and while driving at night.
Discuss all of your contact fitting options with your eye care professional.