The difference between contact lens and eyeglass prescriptions

Most people enjoy both contact lenses and spectacles. There are some individuals who do not like contact lenses. Many reasons are given such as discomfort, poor vision, too much work, I can’t put my finger in my eye, etc. Contact lens wear comes with great responsibility and care should be taken to always have the best fit, prescription and cleaning regime.

Annual eye examinations are important to monitor the health of the eye and fit of the lens. Spectacles are easy, you simply clean them and wear them when required. The ultimate is to be able to wear both types successfully.

When it comes to the prescription, they may vary depending on the degree of far- or nearsightedness, the astigmatism and the addition needed for multifocal wearers. A general rule is that the amount of correction for shortsighted remains the same from -0.25 up to -4.00.

Higher prescriptions are generally reduced. In the case of farsighted eyes, the same rule applies but instead of decreasing the prescription for higher powers, the power is increased.

For example -5.00 becomes -4.75 and +5.00 becomes +5.25. Lenses for astigmatism are great but are limited to powers of -0.75, -1.25, -1.75, -2.25 and -2.75. In most cases good vision is obtained. The axis of astigmatism is also a little restrictive with some modalities of lenses. Generally the axes are in 10 degree steps.

Specialized lenses for higher astigmatic eyes are also available but on order.
The multifocal lens gives good vision for both far and near. However there are some individuals who require better vision and this option is not acceptable due to the design of the lens. For them standard contact lenses with reading glasses might be a better option or simply to stay with spectacles.

At the end of the day, great vision can be obtained with both options. The correct lens type, prescription and fit are very important to achieve contact lens compliance. Every person is individual and the visual needs are different. Today eyecare practitioners are in a position to fit most eyes successfully with contact lenses, irrespective of the correction required.

The final contact lens prescription might look totally different when compared to the spectacle prescription but due to limitations and lens math, that is how it has to be in order to achieve the best possible vision and fit for that contact lens.