Know All About Lenses Index

What do high index lenses mean?

As the name suggests, a lens with high index refers to those eyeglasses which have a higher refractive index. In layman's terms, this essentially means that the lenses have a higher capability of bending the light rays to provide a clear view, especially for people who have a higher power.

When it comes to their appearance, such lenses with a high index are known to be thin around the edges and are also light in weight. High index glasses are recommended for people who have ‘myopic’ eye vision or, in simpler terms, nearsightedness. Such people have a difficulty focusing on objects that are far away from them. However, it is pertinent to note here that these lenses can be used by people who have myopia and also by people who have hyperopia.

Know All About Lenses Index

What do high index lenses mean?

As the name suggests, a lens with high index refers to those eyeglasses which have a higher refractive index. In layman's terms, this essentially means that the lenses have a higher capability of bending the light rays to provide a clear view, especially for people who have a higher power.

When it comes to their appearance, such lenses with a high index are known to be thin around the edges and are also light in weight. High index glasses are recommended for people who have ‘myopic’ eye vision or, in simpler terms, nearsightedness. Such people have a difficulty focusing on objects that are far away from them. However, it is pertinent to note here that these lenses can be used by people who have myopia and also by people who have hyperopia.

Understanding about high index lenses

To understand the working of such glasses, let us first understand why a faulty vision occurs. Well, it is due to a misalignment which can either be in one eye or both the eyes. This creates a problem for the eye to focus an image on the retina, which results in blurry vision. Any prescription glass that an eye specialist recommends would help correct this faulty vision. This can be done either by refracting or bending the light through the lenses. This helps in adjusting the focal point and, thus, helps in getting a clear vision.

Any lenses that have a high index would fall between 1.59 to 1.79 on the index. This is quite different from a standard lens as they have a refractive index of only 1.50. on the other hand, a traditional lens will have a refractive index of 1.53. Thus, it is imperative to understand here that higher the index, the better it will be for bending the rays of the light, which is required to achieve a clear vision.

Even in index lenses, there are certain sub-categories which are mentioned below:

a.      Standard Index Lens – 1.50

b.      Mid Index Lens – 1.56

c.      Thin & Light Index Lens – 1.57

d.      Polycarbonate – 1.59

e.      High Index Lens – 1.61 – 1.74

Understanding about high index lenses

To understand the working of such glasses, let us first understand why a faulty vision occurs. Well, it is due to a misalignment which can either be in one eye or both the eyes. This creates a problem for the eye to focus an image on the retina, which results in blurry vision. Any prescription glass that an eye specialist recommends would help correct this faulty vision. This can be done either by refracting or bending the light through the lenses. This helps in adjusting the focal point and, thus, helps in getting a clear vision.

Any lenses that have a high index would fall between 1.59 to 1.79 on the index. This is quite different from a standard lens as they have a refractive index of only 1.50. on the other hand, a traditional lens will have a refractive index of 1.53. Thus, it is imperative to understand here that higher the index, the better it will be for bending the rays of the light, which is required to achieve a clear vision.

Even in index lenses, there are certain sub-categories which are mentioned below:

a.      Standard Index Lens – 1.50

b.      Mid Index Lens – 1.56

c.      Thin & Light Index Lens – 1.57

d.      Polycarbonate – 1.59

e.      High Index Lens – 1.61 – 1.74

When do you need a high index lens?

Here, we will be mentioning 5 signs which are enough to tell you that you need to get a pair of lenses with a high index.

1.      If the prescription is fairly strong

It is not necessary that only if you have a high power, then you can wear lenses with high index. However, in usual circumstances, such lenses are primarily recommended for people with a higher prescription. The main reason behind this is that people with a high power would normally get a thick traditional lens. On the other hand, if you switch to a high index lens, then the width of these lenses would be cut by half.

If you are still not sure that you should change the lenses or not, it is best if you consult with your eye specialist. They can guide you in a better way.

2.      If your glasses are too heavy

As mentioned above, people with a higher prescription tend to get a thicker lens. Hence, the glasses with such lenses would obviously be heavy. This might be the reason why your glasses keep slipping down the nose. Therefore, a lighter lens will surely benefit you.

Along with this, it is also suggested that when you purchase a new frame, then check its fitting and the comfort it provides thoroughly. One thing you must focus on is that the glasses should not feel too heavy, and they should be able to rest on your face even when you are running or walking.

If it is the weight of the lens that is making the frame of the glasses slip downwards, then switching to a high index lens is the perfect solution to your problem.

3.      If you do not want the bug-eye effect

People with a higher prescription usually get a thicker lens with a noticeable curvature. This might make your eyes look like a bug. Therefore, if you don’t want this bug-eye effect, then you sure should purchase a high index lens which will give your face a different look altogether.

4.      If you want to have more choices

Everyone wants to have a wide variety of choices to choose from. However, there are instances to which only people with a thick lens can relate to. They are often told that a certain frame cannot be made according to them as the width of their lens is too thick. This only reduces the options for people with a higher prescription. Therefore, to avoid any such situation, it is best if you switch to high index lenses as they would be available to you in a thinner lens and will only increase the number of options you have.

This happens especially with metal frames.

5.      If you have an eye strain

It must be noted that even if you have the correct prescription glasses, even then your eyes might feel strained. Our eyes are strained a lot even through the slightest movement as they are very sensitive. To avoid an extra strain that might be caused due to corrective lenses, doctors recommend high index lenses. The reason behind this is that they are able to refract light more than the standard lenses.

This will also be helpful to people who have eyes that are more sensitive to light.

When do you need a high index lens?

Here, we will be mentioning 5 signs which are enough to tell you that you need to get a pair of lenses with a high index.

1.      If the prescription is fairly strong

It is not necessary that only if you have a high power, then you can wear lenses with high index. However, in usual circumstances, such lenses are primarily recommended for people with a higher prescription. The main reason behind this is that people with a high power would normally get a thick traditional lens. On the other hand, if you switch to a high index lens, then the width of these lenses would be cut by half.

If you are still not sure that you should change the lenses or not, it is best if you consult with your eye specialist. They can guide you in a better way.

2.      If your glasses are too heavy

As mentioned above, people with a higher prescription tend to get a thicker lens. Hence, the glasses with such lenses would obviously be heavy. This might be the reason why your glasses keep slipping down the nose. Therefore, a lighter lens will surely benefit you.

Along with this, it is also suggested that when you purchase a new frame, then check its fitting and the comfort it provides thoroughly. One thing you must focus on is that the glasses should not feel too heavy, and they should be able to rest on your face even when you are running or walking.

If it is the weight of the lens that is making the frame of the glasses slip downwards, then switching to a high index lens is the perfect solution to your problem.

3.      If you do not want the bug-eye effect

People with a higher prescription usually get a thicker lens with a noticeable curvature. This might make your eyes look like a bug. Therefore, if you don’t want this bug-eye effect, then you sure should purchase a high index lens which will give your face a different look altogether.

4.      If you want to have more choices

Everyone wants to have a wide variety of choices to choose from. However, there are instances to which only people with a thick lens can relate to. They are often told that a certain frame cannot be made according to them as the width of their lens is too thick. This only reduces the options for people with a higher prescription. Therefore, to avoid any such situation, it is best if you switch to high index lenses as they would be available to you in a thinner lens and will only increase the number of options you have.

This happens especially with metal frames.

5.      If you have an eye strain

It must be noted that even if you have the correct prescription glasses, even then your eyes might feel strained. Our eyes are strained a lot even through the slightest movement as they are very sensitive. To avoid an extra strain that might be caused due to corrective lenses, doctors recommend high index lenses. The reason behind this is that they are able to refract light more than the standard lenses.

This will also be helpful to people who have eyes that are more sensitive to light.

Wearing a lens with a high index has its own benefits. However, when it comes to the eyes of the person, it is best to consult a doctor first before making any final choice. Moreover, keep your comfort above anything.