Understanding the Contact Lens Exam
A standard eye exam evaluates your overall eye health and determines whether you need corrective lenses. It typically includes vision testing, eye pressure measurement, and an examination of the internal and external structures of your eyes. While this exam can result in a prescription for eyeglasses, it does not provide the specific information needed to fit contact lenses.
A contact lens exam includes all the elements of a regular eye exam but goes further with additional measurements and evaluations. Because contact lenses sit directly on the surface of your eye, your eye care provider needs detailed information about the shape, size, and health of your cornea, as well as the quality of your tear film. These factors directly influence which type of contact lens will provide the most comfortable and effective vision correction for your individual eyes.
The contact lens prescription itself is distinct from an eyeglass prescription. It includes parameters such as base curve, diameter, and the specific lens brand or material recommended for your eyes. Two people with the same eyeglass prescription may require very different contact lens specifications based on their unique eye anatomy.
One of the most important measurements taken during a contact lens exam is corneal curvature. Your eye care provider uses an instrument called a keratometer or a corneal topographer to map the shape of the front surface of your eye. The cornea is not perfectly spherical, and these measurements reveal the degree and orientation of its curvature.
Corneal topography creates a detailed, color-coded map of your corneal surface, identifying any irregularities that could affect lens fit. This information helps your provider select a contact lens with the appropriate base curve, which is the measurement that determines how the lens conforms to your eye. A lens with the wrong base curve can slide around excessively, fit too tightly and restrict oxygen flow, or cause discomfort throughout the day.
For patients with conditions such as keratoconus, where the cornea develops an irregular cone-like shape, these measurements become especially important in determining the right type of specialty lens.
Your provider will measure the size of your pupil under different lighting conditions, as pupil diameter changes between bright and dim environments. This measurement is particularly relevant for multifocal contact lenses, where the optical zones of the lens must align properly with the pupil to deliver clear vision at various distances.
The diameter of your iris is also measured to help determine the overall size of the contact lens. A properly sized lens should cover the cornea with a slight overlap to maintain stable positioning while still allowing adequate movement for tear exchange beneath the lens.
The quality and quantity of your tear film play a significant role in contact lens comfort and success. Your provider may perform several tests to evaluate your tears. The tear break-up time test measures how quickly your tear film begins to deteriorate after a blink, indicating tear stability. A Schirmer test uses a small strip of paper placed at the edge of the lower eyelid to measure tear production volume over a set period.
Your provider will also examine the composition of your tear film, which consists of three layers: an oily outer layer that prevents evaporation, a watery middle layer that nourishes the cornea, and a mucous inner layer that helps tears adhere to the eye surface. Deficiencies in any of these layers can affect which lens material and wearing schedule will work well for you. Patients with dry eye concerns may benefit from specific lens materials that retain moisture or from daily disposable lenses that provide a fresh surface each day.
Types of Contact Lenses
Soft contact lenses are made from flexible hydrogel or silicone hydrogel materials that conform to the shape of the eye. They tend to be comfortable from the initial wearing experience, which makes the adaptation period shorter for new wearers. According to the Contact Lens Institute in 2023, soft lenses account for the large majority of contact lens prescriptions in the United States.
Silicone hydrogel lenses allow more oxygen to pass through to the cornea compared to traditional hydrogel materials. Adequate oxygen transmission is important for maintaining corneal health over long-term lens wear. Your provider will recommend the material that suits your wearing schedule, tear film characteristics, and vision correction needs.
Rigid gas permeable lenses, often referred to as RGP or GP lenses, are made from firm, durable materials that maintain their shape on the eye. Because they do not flex like soft lenses, they can provide crisper vision, particularly for patients with higher degrees of astigmatism or irregular corneal surfaces. The rigid design creates a smooth optical surface that compensates for corneal irregularities.
RGP lenses typically require a longer adaptation period than soft lenses. New wearers may notice the lens edges during the first few weeks, but this sensation generally diminishes with consistent wear. These lenses are smaller in diameter than soft lenses and move more freely on the eye with each blink, which promotes healthy tear exchange. With proper care, RGP lenses are durable and can last longer than soft lenses before needing replacement.
Astigmatism occurs when the cornea or lens inside the eye has an uneven curvature, causing blurred or distorted vision at various distances. Toric contact lenses are designed with different powers in different meridians of the lens to correct this uneven curvature. They also incorporate stabilization features that keep the lens oriented correctly on the eye, since the astigmatism correction must remain aligned with the specific axis of your astigmatism.
Both soft and RGP lenses are available in toric designs. The fitting process for toric lenses requires additional precision to verify that the lens rotates to the correct position and remains stable during blinking and eye movement. Your provider may need to try several orientations or designs before finding the one that delivers consistent, clear vision throughout the day.
Multifocal contact lenses address presbyopia, the age-related change in near focusing ability that typically becomes noticeable in a person's forties. These lenses contain multiple prescription zones that allow the wearer to see clearly at distance, intermediate, and near ranges without switching between separate pairs of glasses.
Multifocal designs include concentric ring patterns, where alternating rings of distance and near power surround the center of the lens, and blended designs that gradually transition between powers. Your provider will evaluate your visual demands, including how much time you spend on tasks at various distances, to select the design that provides the most functional vision for your daily activities. Some patients benefit from a monovision approach, where one eye is corrected for distance and the other for near vision.
Daily disposable lenses are worn once and discarded at the end of the day. A fresh lens is used each morning, eliminating the need for cleaning solutions and lens storage cases. This wearing schedule reduces the accumulation of protein deposits, allergens, and microorganisms on the lens surface.
Daily disposables can be a suitable option for patients with allergies, dry eye tendencies, or those who prefer a simplified lens care routine. They are also practical for people who wear contact lenses on a part-time basis, such as during sports or social events, since there is no concern about storage or solution maintenance between wearings. Daily disposable options are available in spherical, toric, and multifocal designs.
What to Expect During Your Visit
Your contact lens appointment begins with a discussion about your lifestyle, visual needs, and any previous experience with contact lenses. Your provider will ask about your work environment, hobbies, sports participation, and how many hours per day you expect to wear your lenses. This conversation helps guide the selection of the most appropriate lens type and wearing schedule.
Your provider will also review your medical and ocular history, including any medications you take, allergies you experience, and conditions such as dry eye or previous eye surgery. Certain health conditions and medications can affect tear production or corneal sensitivity, which may influence your lens options.
After completing measurements and determining your contact lens prescription, your provider will place trial lenses on your eyes. You will wear these lenses for a short settling period, typically fifteen to thirty minutes, allowing them to stabilize on your eyes. During this time, the lenses interact with your natural tear film and settle into their resting position.
Your provider will then evaluate the fit using a slit lamp biomicroscope, examining how the lens moves with each blink, how it centers on the cornea, and whether it provides adequate coverage. For toric lenses, the rotational alignment is assessed to confirm the astigmatism correction is properly oriented. Your vision is tested while wearing the trial lenses to ensure the prescription is accurate at various distances.
If the initial trial lenses do not meet expectations for comfort, vision, or fit, your provider may try alternative lens parameters, materials, or designs. The fitting process can sometimes require multiple visits, particularly for specialty lenses such as multifocal or toric designs.
For new contact lens wearers, your provider or a trained staff member will teach you how to insert and remove your lenses safely. This hands-on training includes proper hand washing technique, how to place the lens on your fingertip and verify it is not inside out, and the correct method for gently placing the lens on your eye. You will practice these skills during your visit until you can perform them confidently on your own.
You will also receive detailed instructions on lens care, including which cleaning and disinfecting solution to use, how to properly rub and rinse your lenses, and how to maintain your lens storage case. It is important to follow the recommended replacement schedule for both your lenses and your storage case to reduce the risk of eye infection and maintain lens performance.
Your Care Journey at Washington Eye Institute
After your initial fitting, you will return for a follow-up visit, typically within one to two weeks. During this appointment, your provider evaluates how your eyes have responded to the lenses after extended wear. This includes checking for any signs of corneal stress, verifying that your vision remains clear and stable, and discussing your comfort level throughout the day.
Annual contact lens evaluations are an important part of maintaining healthy lens wear over time. At each annual visit, your provider reassesses your prescription, examines your corneal health, and evaluates whether your current lenses continue to meet your needs. Changes in your prescription, tear film, or eye health may prompt an adjustment to your lens type or wearing schedule.
Most people who need vision correction can wear contact lenses successfully. Good candidates include individuals with myopia, hyperopia, astigmatism, and presbyopia. Active individuals who find glasses inconvenient during sports or physical activities often benefit from contact lens wear, as do those who prefer not to alter their appearance with eyeglass frames.
Successful contact lens wear does depend on a willingness to follow proper care and handling instructions. Patients who are comfortable with touching their eyes and committed to maintaining their lens care routine tend to have the most positive experience. Your provider will discuss any specific factors in your eye health or lifestyle that may affect your candidacy and help you determine whether contact lenses are a practical choice for you.
Washington Eye Institute offers contact lens exam and fitting services at our locations in Greenbelt, Rockville, and Cumberland, Maryland. Each office is equipped with the diagnostic instruments needed to perform thorough contact lens evaluations and fittings. Whether you are considering contact lenses for the first time or looking to update your current prescription, our team is available to guide you through the process at a location convenient to you.
Scheduling a contact lens consultation is a straightforward first step. During your visit, your provider will take the time to understand your goals and answer any questions about the fitting process, lens options, and what to expect as you begin wearing your new lenses.
Questions and Answers
A contact lens exam and fitting typically takes longer than a standard eye exam. You should plan for the appointment to last between sixty and ninety minutes. This time includes the eye exam, additional contact lens measurements, trial lens fitting, and instruction on lens insertion, removal, and care. Specialty fittings for multifocal or toric lenses may take additional time, and follow-up visits are usually shorter.
Many patients with mild to moderate dry eye symptoms can wear contact lenses with the right approach. Your provider will evaluate your tear film and may recommend specific lens materials that retain moisture more effectively, daily disposable lenses that provide a fresh surface each day, or lenses with a lower water content that resist dehydration. In some cases, treating the underlying dry eye condition before or during lens wear can improve comfort. Your provider will work with you to find a solution that balances vision correction with ocular comfort.
Replacement schedules vary by lens type and are set by your provider. Daily disposable lenses are discarded after a single use. Bi-weekly lenses are replaced every two weeks, and monthly lenses are replaced every thirty days, regardless of how many days you actually wore them during that period. Exceeding the recommended replacement schedule increases the risk of protein and lipid buildup on the lens surface, which can lead to reduced comfort, blurred vision, and a higher risk of eye infection. Your provider will specify the correct schedule for your particular lenses.
Occasional mild discomfort can result from a dry environment, extended screen time, or allergens. Rewetting drops approved for use with contact lenses can help relieve temporary dryness. However, if you experience persistent discomfort, redness, pain, blurred vision, or sensitivity to light, you should remove your lenses and contact your provider. These symptoms may indicate a lens fit issue, a corneal abrasion, or an infection that requires prompt evaluation. It is important not to continue wearing lenses that cause ongoing discomfort without seeking professional guidance.
Contact lenses can be appropriate for younger patients when they demonstrate the maturity and responsibility needed for safe lens handling and care. Many adolescents and some children adapt well to contact lens wear, particularly for sports and other activities where glasses may be impractical. According to the American Academy of Ophthalmology in 2022, children as young as eight have been shown to handle contact lens care effectively in supervised settings. Your provider will assess your child's readiness based on their hygiene habits, motivation, and ability to follow care instructions.
Yes, having a current pair of eyeglasses is recommended even if you wear contact lenses as your primary form of vision correction. There are situations when you should not or cannot wear your lenses, such as during an eye infection, when experiencing unusual discomfort, or when swimming. Eyeglasses serve as a reliable backup and allow your eyes to rest from lens wear when needed. Your provider can ensure both your contact lens and eyeglass prescriptions are up to date at your annual examination.