Contact Lenses Eye Care Doctors, Prescription Eye Exam

Can I wear Contact Lenses?
- With the newest contact lens designs and materials available today, our doctors are able to fit patients who may not have had success wearing contact lenses in the past. Whether due to poor vision, astigmatism, comfort issues, or dry eyes there are many more choices in contact lens materials to meet those challenges.

What types of Contacts Lenses are there and which lens is right for me?
- There are several types of Contact lenses but only a thorough examination of your eyes AND your lifestyle will reveal the answer. A few types are:
  
  Daily Disposables
  The shortest replacement schedule is single use (daily disposable) lenses, which are disposed of each night. These may be best for patients with ocular allergies or other conditions, because it limits deposits of antigens and protein. Single use lenses are also useful for people who use contacts infrequently, or for purposes (e.g. swimming or other sporting activities) where losing a lens is likely.
  
  Two-week Replacement Disposables
  The main advantage of wearing disposable lenses is that you put a fresh pair of lenses in your eyes every two weeks. Another advantage is ease of care with multipurpose solutions.
  
  One-month Replacement Disposables
  Similar to two-week replacement lenses but you throw them out every 30 days.
  
  Conventional Contact Lenses
  These are the original soft contact lenses. It is recommended these lenses be replaced on a yearly basis. Conventional lenses are more care intensive than disposable lenses.
  
  Color Contact Lenses
  Certain soft contact lenses come in colors to either enhance your eye color or completely change it.
  
  Toric for Astigmatism
  Toric lenses are made from the same materials as regular contact lenses but have a few extra characteristics:
  • They correct for both spherical and cylindrical aberration.
  • They may have a specific 'top' and 'bottom', as they are not symmetrical around their center and must not be rotated. Lenses must be designed to maintain their orientation regardless of eye movement. Often lenses are thicker at the bottom and this thicker zone is pushed down by the upper eyelid during blinking to allow the lens to rotate into the correct position (with this thicker zone at the 6 o'clock position on the eye). Toric lenses are usually marked with tiny striations to assist their fitting.
  • They are usually more expensive to produce than non-toric lenses
  
  Bifocal Contact Lenses
  Multifocal soft contact lenses are more complex to manufacture and require more skill to fit. All soft bifocal contact lenses are considered "simultaneous vision" because both far and near vision corrections are presented simultaneously to the retina, regardless of the position of the eye. Of course, only one correction is correct, the incorrect correction causes blur. Commonly these are designed with distance correction in the center of the lens and near correction in the periphery, or vice versa.

What's involved in a Contact Lens Exam?
- In an initial exam, the eye doctor will examine your eyes to determine if you can wear contact lenses. Your prescription and the curvature of your eye are measured and the doctor will discuss any special needs you may have. The doctor will then determine the type of contact lenses that best fit your eyes and provide you with the most accurate vision while ensuring that your eyes remain healthy with the lenses.
  
  If trial lenses are available in the office, you may be able to go home with lenses the same day. However, if your prescription or curvature warrant, contact lenses may need to be ordered and a contact lens fitting appointment scheduled when the lenses arrive.

What's involved in a Contact Lens Fitting?
- When the lenses are ready, a fitting examination is scheduled as a practice session for you to try your new lenses and to become adept at lens insertion and removal. The doctor will also look at the lenses on your eyes and determine if any changes need to be made.

Why is a yearly Contact Lens exam important?
- Seeing 20/20 isn't the only reason for a contact lens exam. Since the eye is a sensitive organ, it is susceptible to irritations that may be caused by contact lens wear.
  
  Problems that are undetectable to you can develop into more serious conditions. It is vital to your eye health to make sure that your contact lenses fit properly and are allowing enough oxygen to reach the cells of the cornea. During the annual contact lens exam, your eye care professional evaluates the condition of the lenses and can tell if any changes are warranted in the lenses’ fitting.

Can I swim or shower with Contact Lenses on?
- There are two main reasons why you should not swim or shower with your contact lenses - possible loss of the lenses and, most importantly, contamination of the lenses.
  
  Underwater, contact lenses may be washed out of your eye, or above water a small wave or splash may take the lens with it. Contact lenses, especially the soft variety, will absorb any chemicals or germs in the water. They will then stay in or on the lens for several hours, irritating the eyes and possibly causing infection.

Can children wear Contact Lenses?
- The deciding factor for whether a child should wear contact lenses should be that child's maturity level. Children of all ages can tolerate contact lenses well, but they must be responsible for the care of the lenses. Parents should make that judgment based on the child's personal hygiene habits and their ability to perform household chores.

What is the difference between soft and hard Contact Lenses?
- Hard lenses
  These lenses were the original contact lenses made several decades ago from a plastic called PMMA. For a long time they were the only kind of lens but they are seldom used anymore as they have several drawbacks and have been superseded by “rigid” lenses. Rigid, or gas permeable, lenses are similar to hard lenses in design and appearance, however as the name suggests, the material they are made of is permeable to gases.
  
  Soft lenses
  Soft lenses are slightly larger and more flexible than rigid or hard lenses. Soft lenses are made of materials which soak up water, and it is this uptake of water that allows oxygen to transfer to the cornea. Soft lens material itself is impermeable, so the oxygen is transmitted via the water.

Why shouldn't I wear my two-week disposable lenses longer?
- In order to maintain optimal eye health and comfort, it is important to adhere to the wearing schedule prescribed by your doctor.

What if I don't wear my two-week disposable contacts every day?
- The two-weeks timeframe refers to 14 days of wear. If you are wearing lenses only two to three days per week, the lenses may last longer then two weeks.

Can I safely wear extended wear Contact Lenses overnight?
- Extended lens wearers may have an increased risk for corneal infections and corneal ulcers, primarily due to poor care and cleaning of the lenses, tear film instability, and bacterial stagnation. Corneal neovascularization has historically been a common complication of extended lens wear, though this does not appear to be a problem with silicone hydrogel extended wear.
  
  The most common complication of extended lens use is conjunctivitis, usually allergic or giant papillary conjunctivitis (GPC), sometimes associated with a poorly fitting contact lens.

What are all those numbers for my prescription?
- An eyeglass prescription is written in a standardized format so it can be understood globally. The right eye, is generally referred to as "OD" or "R", while the left eye is generally referred to as "OS" or "L". The right eye is almost always on top in a written prescription with the left directly below. Ignoring for sample sake, the right or left eye, let's look at a example below:
  
  -2.00 -1.00 x 90. The first number (-2.00) tells us the spherical refractive diopter (a unit of measurement) needed to correct (farsightedness or nearsightedness). In this example, a minus sign in front of the number indicates a correction for nearsightedness. A plus sign would indicate a correction for farsightedness. This is generally true when you are talking about the first set of numbers.
  
  The plus and minus signs on the second number, generally indicates what professional examined your eyes. An optometrist usually refracts in what's referred to as "Minus Cylinder, while an ophthalmologists refracts in "Plus Cylinder". For example, an optometrists script would be -2.00 -1.00 x 90, while the same prescription written by an ophthalmologists would be; -3.00 +1.00 x 180. Please note that the second number has a plus sign, and the last number (180, the Axis) has been transposed 90 degrees.
  
  The second number (-1.00) is for astigmatism. If there is no astigmatism correction needed then you would not see the third (180) number. Sometimes you might see the following; SPH written for a cylinder correction instead of a number and nothing written for the third number. SPH stands for "Sphere" which indicates that there is no astigmatism correction needed.
  
  The next number (180, the Axis line) is the direction of the astigmatism. Astigmatism can be measured in any direction around the clock. We use the numbers from 001 to 180 to indicate the orientation of the correction needed.
  
  The next number is the Base Curve (BC). This number indicates how curved the inside of your lens is. It typically ranges from 8-10 and assures that the lens fits well against your eye so it feels comfortable. A lower number means a steeper curve, and a higher number means a flatter curve.
  
  The next number is the Diameter (DA). This is the width of the contact lens from edge to edge, measured in millimeters. This helps ensure that your contact lens will properly cover your eye.
  
  Depending on your need, there may be additional numbers in a Contact Lens prescription as well. If your prescription has a set of numbers, or a single number with a symbol such as a triangle, or the letters " BI, BO, BU, or BD that would indicate a prism correction. BI = Base In, BO = Base Out, BU = Base Up, and BD = Base Down. It is not uncommon to have different base directions for either eye.
  
  Also, you might see "ADD" numbers for those requiring intermediate or near vision help. The ADD number is exactly what it indicates...; an ADD, or an additional script to an otherwise already existing prescription. For example, your prescription is -2.00 for the first number. (In this example there is no astigmatism). For the "ADD " number you have a +3.00.This would indicate that by 'Adding" the +3.00 to the -2.00, your reading prescription would be +1.00 (adding a greater positive number to a lesser negative number results in a positive answer).
  
  Also, you might see "Color". The color of a contact lens typically has no effect on your vision, but it's still important to get a prescription for them to make sure they fit your eyes properly.

Do I need an optometrist and or an ophthalmologist?
- Both are eye doctors that diagnose and treat many of the same eye conditions. The American Optometric Association defines Doctors of Optometry as: primary health care professionals who examine, diagnose, treat and manage diseases and disorders of the visual system, the eye and associated structures as well as diagnose related systemic conditions. They prescribe glasses, contact lenses, low vision rehabilitation, vision therapy and medications as well as perform certain surgical procedures.
  
  The main difference between the two, is that ophthalmologists perform surgery, where an optometrist would not, preferring to specialize in eye examinations, as well as eyeglass and contact lens related services.
  
  Optometrists would be involved in all of the pre- and post-operative care of these patients; collecting accurate data, educating the patient, and insuring proper healing after the procedure. An ophthalmologist is more of a medical related specialist, who would need only to be involved if some kind of surgery were being considered. An optometrist can treat most any eye condition, including the use of topical or oral medications if needed. This might include the treatment of glaucoma, eye infections, allergic eye conditions and others, to name just a few.
  
  A third "O" that often is overlooked, is the optician. An optician is not a doctor, and they cannot examine your eye under their own license. However, a highly trained optician plays an indispensable role in the most successful eye doctors' offices. An optician most often handles the optical, contact lens, and glasses side of things. Based on their vast knowledge of lenses, lens technology and frames, they manufacture eyeglasses, as well as assist in the selection of eyewear, based on the requirements of each individual patient.