Most people know that glasses help blurry vision. However, some glasses do something different. Prism glasses help the eyes work together.
They do not make images sharper. Instead, they move images. As a result, the eyes do not need to work as hard.
For many people, prism glasses reduce eye strain. In addition, they can help with double vision, headaches, and fatigue. Because of this, many patients feel more comfortable during daily activities.
Although prism lenses sound complex, the idea is simple.
What Is a Prism?
A prism bends light.
When light passes through a prism lens, the image moves. As a result, the eyes can line up more easily.
A regular lens helps you focus. In contrast, a prism changes where an image appears.
Think of it like moving a target. Instead of making your eyes work harder, the prism moves the image into a better spot. Therefore, the eyes can work together more comfortably.
How Do Your Eyes Work Together?
Your eyes are a team.
Each eye sees a slightly different view. Then, the brain combines both images into one.
Most of the time, this happens without effort. However, the system works best when both eyes point at the same object.
Sometimes, the eyes do not point to the same place. As a result, the brain receives two different images.
Consequently, symptoms can occur.
These symptoms may include:
- Double vision
- Eye strain
- Headaches
- Blurry vision
- Fatigue
- Dizziness
- Trouble reading
In some cases, people do not realize their eyes are working too hard. Nevertheless, the symptoms can still affect daily life.
How Do Prism Glasses Help?
Prism lenses move the image seen by one eye.
As a result, both eyes see the same thing. Therefore, the brain can combine the images more easily.
Because the eyes do less work, many symptoms improve. For example, reading may feel easier. In addition, computer use may become more comfortable.
Furthermore, many patients notice relief soon after getting prism glasses.
What Does Prism Correct?
Prism glasses can help several eye conditions.
Double Vision
Double vision is also called diplopia.
People with double vision see two images instead of one.
The images may appear:
- Side by side
- One above the other
- At an angle
This often happens when the eyes are not aligned. As a result, the brain struggles to combine the images.
Prism lenses move one image closer to the other. Consequently, the brain can create a single image.
For many people, this provides quick relief.
Strabismus
Strabismus means the eyes are not lined up.
One eye may turn inward. Alternatively, it may turn outward. In other cases, it points up or down.
Because the eyes point in different directions, vision can become uncomfortable. As a result, symptoms such as eye strain or double vision may occur.
Prism glasses may help reduce these symptoms. In some cases, vision therapy may also help. Additionally, surgery may be recommended for certain patients.
Convergence Insufficiency
This condition affects near tasks.
Normally, the eyes turn inward when reading. However, some people have trouble making this movement.
As a result, reading may become difficult.
Common symptoms include:
- Eye strain
- Headaches
- Poor focus
- Losing your place while reading
Prism lenses can make near work easier. Therefore, many patients feel more comfortable while reading. In addition, they may find it easier to work on computers or tablets.
Nerve Problems
The nerves that move the eyes can become weak or damaged.
This may happen because of:
- Diabetes
- Stroke
- Head injury
- Other health conditions
When the nerves do not work well, the eyes may become misaligned. Consequently, double vision often occurs.
Prism glasses can help reduce these symptoms. Meanwhile, doctors can monitor the underlying condition.
Concussions and Brain Injuries
A concussion can affect how the eyes work together.
Even a mild injury may cause vision problems.
Some people notice:
- Eye strain
- Dizziness
- Trouble reading
- Balance issues
- Motion sensitivity
In these cases, prism lenses may improve comfort. As a result, daily tasks may become easier. Furthermore, some patients report better visual stability.
How Is Prism Measured?
Prism is measured in prism diopters.
The doctor also chooses a direction.
The direction may be: base in, base out, base up or base down.
The amount and direction depend on the eye problem. Therefore, careful testing is important.
During an eye exam, your doctor will determine the correct prescription.
Are Prism Glasses Different From Regular Glasses?
Yes.
Regular glasses improve focus.
They help correct:
- Nearsightedness
- Farsightedness
- Astigmatism
Prism glasses help eye alignment.
Instead of making images clearer, they move images.
Some people need only prism. Meanwhile, others need both prism and a standard prescription.
Fortunately, both corrections can often be placed in the same lens. As a result, patients do not usually need separate pairs of glasses.
Do Prism Glasses Look Different?
Usually, no.
Most prism lenses look like regular glasses.
Small amounts of prism are often impossible to notice. Therefore, most people will not see a difference.
Higher amounts may create thicker lens edges. Even then, modern lens designs help reduce this effect.
As a result, prism glasses often look very similar to standard eyewear.
How Long Does It Take to Adjust?
Everyone is different.
Some people feel better right away. Others need a few days.
During the adjustment period, you may notice:
- Mild distortion
- A change in depth perception
- Awareness of the new lenses
These feelings usually improve with time.
As your brain adjusts, vision becomes more natural. Therefore, it is important to wear the glasses as directed.
If symptoms continue, then a follow-up visit may be helpful.
Can Prism Change Over Time?
Yes.
Some prescriptions stay the same for years. However, others change over time.
Changes may happen because of:
- Eye muscle changes
- Health conditions
- Recovery from injury
- Eye surgery
For this reason, regular eye exams are important.
These visits help your doctor monitor your vision and eye alignment. In addition, they allow the prescription to be updated when needed.
Are Prism Glasses the Only Treatment?
Not always.
The best treatment depends on the cause.
Treatment options may include:
- Prism glasses
- Vision therapy
- Surgery
- Medical treatment
- Monitoring
Many people do very well with prism lenses alone. However, some conditions need additional care.
Therefore, a complete eye exam is important. Afterward, your eye doctor can recommend the best option.
When Should You Ask About Prism?
Consider an eye exam if you have:
- Double vision
- Frequent headaches
- Eye strain
- Visual fatigue
- Reading problems
- Trouble focusing
- Dizziness linked to vision
These symptoms can have many causes. However, eye alignment problems are one possibility.
Therefore, an eye exam can help find the answer. Early treatment may also improve comfort more quickly.
The Bottom Line
Prism glasses help the eyes work together. They do this by moving images into a better position. As a result, the brain can combine what each eye sees more easily.
Because of this, many people find relief from double vision, eye strain, headaches, and fatigue. In addition, reading and computer use often become more comfortable.
Most importantly, prism lenses can improve quality of life for people with eye alignment problems. Therefore, if you struggle with these symptoms, ask your eye doctor about prism testing. The right prism prescription may help you see more comfortably every day.
Schedule your appointment at 1 of our 4 conveniently located offices in San Jose, San Mateo, San Ramon, and Juneau.
