As optometrists, we have to make decisions on which contact lenses are right for each individual patient. This is one of the many reasons why optometrist fight to keep money hungry online websites from being allowed to change contact lens brands because it might not be right for the patient’s eyes. Whether a patient is brand new to contacts or currently wears, how the contact lens interacts with the patient’s eye needs to be examined.
Contact lenses are classified as type II medical devices, which can cause a moderate risk to patient’s health who abuse contact lenses by sleeping in them or wearing them longer than instructed by their eye care professional.
Just like clothing stores, there are many contact lens manufacturers that make different types of contacts. It goes beyond the old debate of hard versus soft contact lens, but technology has advanced considerably in the last decade. There are many types of contact lenses differing in curvature, wear schedule, material and more.
The first decision when choosing contact lenses needs to be, which contact will fit best.
An instrument, called a corneal topographer, used to topographically map the cornea, reads the curvature of the cornea. Some patients have a steeper than average cornea, which is described as being more bowl-shaped verses having a flatter than average cornea, which is more plate-shaped. When a contact does not match the curvature of the eye, discomfort and bad vision occur. Not all contact lens manufacturers make contacts that fit both curvatures. Typically, they make contacts that fit the majority of patients, which is the flatter curve.
The second decision is wearing schedule.
Dailies, bi-weekly, and monthly wear schedules depends on the patient’s needs. Some patients need a contact that is replaced more frequently, like dailies, to obtain greater eye health versus others that a bi-weekly or monthly change schedule is better. Eye health, visual needs, occupations, and more need to be considered when choosing contact lens wear schedules. Next to consider is contact lens material. Again, like clothing, some patients might not like cotton, polyester, wool, or blended materials. The contact lens rests on the eye and the material itself can irritate the eye to make the lens uncomfortable. Changing manufactures to obtain a different contact lens material is often needed so that the patient can obtain more all-day comfort.
Finally, the correct prescription is needed to be prescribed for each individual patient.
Farsightedness, nearsightedness, and astigmatism can be all factors in a patient’s prescription. While glasses rest in front of the eyes, the contact lens rests on the eye itself and that can change the prescription. This is why glasses prescriptions and contact lens prescriptions are different and why an additional contact lens examination is needed.
Ultimately, contacts differ from manufacturer to manufacturer due to patent licensing.
Materials used diameter size, visual zones, thickness, and even edge design (rounded vs. chiseled vs. knife-shaped edge designs). Contact lenses are so much more than a one size fits all product. The Food and Drug Administration approves some contact lenses to be slept in while others do not meet the guidelines for healthy over nightwear. However, the West Texas wind and allergies may not allow the patient to successfully and comfortably sleep in those contacts.
Talk to your optometrist today because lasting damage can be caused by contact lenses that aren’t right for your eyes. Remember, take care of your eyes because they are the only set you will ever have.