subject: Contact Lens Prescription vs. Spectacle Prescription [print this page] Contact Lens Prescription vsContact Lens Prescription vs. Spectacle Prescription
Nowadays, the number of people who wear glasses is on the rise. People are likely to wear contacts lenses as another option in order to avoid discomfort resulting from prescription glasses. Many people have both prescription glasses and contacts lenses to cope with their defective vision. When they purchase contact lenses or glasses, they may find the contact lens prescription is not always the same as the spectacle prescription. In fact, many people wonder if their regular prescription will work for contact lenses as well. Conversion between a glasses prescription and a contact lens prescription is so important that you should get the accurate prescription from professional optometrist.
1 Over-refraction
Experts declare that it is true that the contact lens prescription will be adjusted by 0.25D.
2 Astigmatic patients
If you have hard contact lenses, you can ignore any astigmatism. A hard contact will correct the shape of the eye by making it more spherical. Therefore, the lenses prescription will be similar to your glasses prescription. If you wear toric lenses, the lenses may lay on the eye. If so, the optometrist may give you a contact lens that has a different axis to the spectacle axis.
3 Prescription availability
It is said that most soft disposable contact lenses are effective in 0.25D increase to a certain degree. The higher plus and minus prescription are effective only in 0.50D rise. If your prescription doesn't work, the optometrist will select the closest available prescription.
4 Different positions
When it comes to positions, contact lenses lay on the eyes, while your glasses are a few millimeters away from your eyes. So contact lenses will be a little bit weaker. You need to get the accurate prescription with the help of an optometrist. Besides, various factors may affect your prescription, especially when your prescription is greater than +/- 4D.
In general, your glasses prescription may slightly differ from your contact lenses prescription, because the strength of the glass is not identical to that of the contact lenses. However, the glasses prescription is quite close to contact lenses prescription. In my opinion, it is advisable to consult the professional optometrists before you buy contact lenses.
