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How is toric contact lens prescription calculated?
- Sphere power = +5.00 D –> +5.00 + vertex factor of +0.25 D = +5.25 D at 180th meridian.
- Sphere + Cylinder power = +5.00 – 1.00 = +4.00 D –> +4.00 + VF of +0.25 = +4.25 D at 90th meridian.
- Adjusted Cylinder power = -1.00 D + VF of +0.25 = -0.75 D.
Can you convert your glasses prescription to contacts?
Unfortunately, you can’t use your current glasses prescription for contact lenses. While both can correct your vision, your prescription for glasses differs from a contact lens prescription in many ways.
How do I figure out my contact lens prescription?
You can find your prescription on the piece of paper given to you by your optician during a check-up, on the end/side of your contact lens box or on the blister packs that contain your contact lenses.
Should my contact lenses be the same prescription as my glasses?
This is because glasses are perched on your nose, at a short distance from your eyes, whereas contact lenses sit on the surface of your eye. Therefore, the two need different prescriptions to give you the best vision correction, and you should not transfer your prescription manually from glasses to contacts.
Are eye exams different for contacts and glasses?
An eyeglass prescription is no substitute for a contact lens exam because the two are very different. An eyeglass prescription measures for lenses that are positioned approximately 12 millimeters from your eyes; whereas a contact lens prescription measures for lenses that sit directly on the surface the eye.
Can I measure my own astigmatism?
At-home astigmatism testing, where you conduct the exam yourself, is not going to get accurate enough data points to determine what prescription of glasses or contacts you need to correct astigmatism. However, it can help you determine if you have astigmatism.
How do you read a astigmatism prescription?
Of the three numbers on your contacts or glasses prescription, the last two refer to astigmatism: Spherical indicates whether you are nearsighted or farsighted. A plus sign indicates you are farsighted, a minus sign indicates you are nearsighted. The higher the number, the stronger your prescription.
What are contacts for astigmatism?
Toric contact lenses are often the best choice for contact lens wearers with an astigmatism, because they’re specifically designed to address the problem. The special shape of a toric lens creates different refractive, or focusing, powers that can help correct either a corneal or a lenticular astigmatism.
How do I use the toric calculator?
Our Toric Calculator* can help. One eye at a time, simply enter the patient’s spectacle prescription and vertex to begin. Click the “Calculate” button. Then select the patient’s lens modality.
How do I use the toric calculator for astigmatism?
Fitting astigmatic patients with lenses can present unique challenges. Our Toric Calculator* can help. One eye at a time, simply enter the patient’s spectacle prescription and vertex to begin. Click the “Calculate” button. Then select the patient’s lens modality. The results will include: The calculated theoretical power.
How do I calculate the theoretical power of a toric lens?
Our Toric Calculator* can help. One eye at a time, simply enter the patient’s spectacle prescription and vertex to begin. Click the “Calculate” button. Then select the patient’s lens modality. The results will include: The calculated theoretical power.