How to choose the right contact lenses for your prescription: a guide to SPH, CYL, and ADD

Choosing contact lenses isn't always as simple as looking at a number on a prescription. Before buying, it's important to understand some basic values of your prescription, such as SPH, CYL, or ADD, as each indicates a different visual need.

In this guide, we explain how to interpret your prescription to know if you need spherical contact lenses, toric contact lenses, or multifocal contact lenses.

What data you should check before buying contact lenses

When you look at an eye prescription or a contact lens box, several values usually appear. The most important ones to know what contact lenses you need are:

SPH or sphere, which indicates the main prescription.

CYL or cylinder, which is related to astigmatism.

ADD or addition, which usually appears when there is presbyopia or tired eyesight.

Understanding this data helps you avoid errors when choosing your contact lenses and check if the product you are buying truly adapts to your prescription.

What SPH means in contact lenses

The SPH value, also called sphere, indicates the main power of your contact lenses. It usually appears with a negative or positive sign.

For example:

SPH -2.50
SPH +1.50
SPH -4.00

If the SPH value is negative, it usually indicates myopia (nearsightedness). That is, difficulty seeing distant objects clearly.

If the SPH value is positive, it usually indicates hyperopia (farsightedness). In this case, there may be difficulty focusing up close or a feeling of eye strain, depending on the person.

This is the first piece of information you should check before choosing your contact lenses.

What CYL means in contact lenses

The CYL value, or cylinder, is related to astigmatism.

If your prescription shows CYL 0.00 or no cylinder value appears, it usually means you don't need specific correction for astigmatism.

However, if a value other than zero appears, such as:

CYL -0.75
CYL -1.25
CYL -1.75

it may indicate that you have astigmatism and need toric contact lenses.

This is important because spherical contact lenses correct myopia or hyperopia, but they do not correct astigmatism in the same way as a toric lens.

What ADD means in contact lenses

The ADD value means addition and usually appears when there is presbyopia or tired eyesight.

For example:

ADD +1.00
ADD +1.50
ADD +2.00

If ADD appears on your prescription, it usually means you need a solution to see well both far and near. In many cases, this is corrected with multifocal contact lenses.

Presbyopia usually appears with age and can be noticed when reading, looking at a mobile phone, or focusing on near objects.

What type of contact lens you need according to your prescription

Based on the values that appear on your prescription, you can guide yourself as follows:

This table serves as a basic guide, but it's always advisable to check your complete prescription before buying.

What contact lenses OpticVue currently offers

Currently, OpticVue offers spherical contact lenses, designed to correct myopia and some degrees of hyperopia depending on the range.

Within OpticVue you can find:

HydroPlus, indicated for myopia.

HighOxygen, indicated for myopia and hyperopia.

If you have astigmatism or need multifocal contact lenses, carefully check your prescription before buying, as you might need a different type of contact lens.

Difference between spherical, toric, and multifocal contact lenses

Spherical contact lenses are the most common and are used to correct myopia or hyperopia.

Toric contact lenses are designed to correct astigmatism. Their design is different because they need to adapt to a more specific prescription.

Multifocal contact lenses are designed for people with presbyopia or tired eyesight, as they help to focus at different distances.

Therefore, before buying contact lenses online or at a pharmacy, it's not enough to just look at the sphere number. You must also check if values like CYL or ADD appear.

Common mistakes when choosing contact lenses

One of the most common mistakes is to buy contact lenses by only looking at the SPH value. Although this data is very important, it is not always sufficient.

It is also common to confuse glasses prescriptions with contact lens prescriptions. In some cases, they may coincide, but they are not always exactly the same.

Another common mistake is to ignore values like CYL or ADD. If they appear on your prescription, they may indicate that you need a specific type of contact lens.

So, how do I know which contact lenses to buy?

To find out which contact lenses you need, check these three points:

First, look at the SPH value to know if your prescription is negative or positive.

Then, check if CYL appears. If the cylinder is not 0, you may need toric contact lenses.

Finally, check if ADD appears. If this value appears, you may need multifocal contact lenses.

If only SPH appears and you have no CYL or ADD values, we would normally be talking about spherical contact lenses.

Conclusion

Understanding your prescription is key to choosing the right contact lenses. Values like SPH, CYL, and ADD help you know if you need spherical, toric, or multifocal contact lenses.

Before buying, always check your prescription or the box of your previous contact lenses. And if you have doubts about whether your prescription corresponds to spherical, toric, or multifocal contact lenses, it is best to check with an eye care professional.

At OpticVue, we want buying contact lenses to be easier, but also clearer. Therefore, checking your prescription before choosing is the first step to getting it right.

Professional Advice