Grab some coffee and stay a while

Optically Aware: things you should know about your contact lens

post feature image

Dr. Marc Weinstein

post feature image

Using contacts is basic, but there is other remotely related information that you ought to be aware of to effectively use contact lenses. Here are some of them.

Is my contact lens prescription the same as my eyeglass prescription?

No, it is not. For starters, the positioning of your lens is different from that of your glasses. While your lens is placed directly on the eye, the glasses sit slightly farther away. Thus, the test for your eyes is carried out to examine and measure something different from what will be examined in the case of a lens. As such, the prescriptions are entirely different. Also, cylinder and acid values are mostly prescribed for glasses while they are not for lenses.

Can I ask my doctor for my prescription?

The Fairness to Contact Lens Consumers Act of America grants American contacts lens consumers certain rights. One of these rights is the right to get their prescriptions from the doctors. It also gives them the liberty to take the prescription to any other vendor whenever they need replacements. This responsibility is not placed on only doctors but prescribers generally. They are obligated to give the patient a copy of the prescription after a test, even if the patient does not ask for it. The prescribers may be the ones to have the prescription over to any vendor or third party whom the patient assigns.

In 2004, the Federal Trade Commission (or FTC, as it is abbreviated, is an independent agency of the American government whose major duty is to enforce civil United States antitrust law and ensure consumer protection) released the contact lens rule, which contains practical obligations of prescribers towards protecting contact lens consumers.

It reiterates the position of the Contact Lens Consumers Act on granting prescriptions to patients even when they don't ask. It further mandates prescribers who has some financial interest either through sale or otherwise to:

·       Offer confirmation statements to patients who would sign that they got their prescription. This statement might either be an acknowledgment receipt, the prescriber's retained copy of the examination, or a prescription.

·       This statement is to be kept for the prescriber for at least three years. In case the patient refuses to sign, the prescriber should take note of this refusal and keep it for 3 years.

·       In case the prescriber sends an electronic version of the prescription, he must keep records that it was sent, or that the patient received, accessed, or downloaded it. These records should also be kept for at least 3 years.

·       The prescriber is also mandated to forward the prescription to any third party as designated by the patient in no later than 40 business hours.

·       Whenever a patient makes a verification request, the prescriber is obligated to point out expirations, invalidities and correct any inaccuracies he notices.

·       While carrying out verification, he must also not demand the patient to buy a contact lens, sign a waiver, or pay extra fees in exchange for a copy of the prescription.

What are the different types of contact lenses?

There are several factors by which contact lenses can be categorized. From their materials to their effects and durability. In terms of effects, here are a few

·       Toric lens has different optical powers in two orientations perpendicular to each other. This lens mostly takes the form of a spherical and cylindrical lens. They are mostly used to correct astigmatism.

·       Single Vision Lenses: this kind of lens has only one corrective power. They are mostly used for nearsightedness, sightedness, astigmatism, or single vision problems.

·       Multifocal lenses: they are created to cater to two or more vision problems. They are mostly recommended for presbyopia and astigmatic patients.

·       Transition lenses are lenses that are technologically designed to respond to brightness. They get dim when there's light and brighten up when the environment is dim.

·       Cosmetic contact lenses are primarily worn to enhance or change eye color. They can also be recommended for vision problems or simply be used for theatrical or fashion purposes.

What do these terms mean in contact lens descriptions?

·       Dk/t:  this indicates how much oxygen can pass through contact. The Do/t is obtained by dividing the Dk which is the permeability of the material by t, which is the thickness of the material.

·       Visitint: VISITINT® is a term that is owned and trademarked by Ancon. It is used to indicate that a contact lens is tinted with either light-blue or light green.

·       Bifocal vs multifocal: this refers to a comparison between bifocal and multifocal lenses. The major difference between these two is that bifocal lenses can correct only two vision issues while multifocal lenses are designed to correct more than two issues.

·       Lens markings: they are markings in your lens which are majorly used to guide the patient towards fitting the lens correctly.

·        water content: This refers to the percentage of water that the lens material contains. The more percentage of water the lens is made of, the more oxygen it can allow to get to the cornea. Therefore, the water content of the lens determines how healthy the contact is for the eye.