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Fisheye lenses capture ultra wide-angle shots while distorting the image into a round, center-magnified view. This view is used for several types of shots, including landscapes and sky photography. Their unique build and optics tend to be on the expensive side, with lenses costing hundreds or thousands of dollars. However, a cheaper alternative exists: Fisheye lens adapters, which screw onto the filter threads of your existing lens and mimic the behavior of a dedicated fisheye lens. Unlike a fisheye lens, fisheye lens adapters have different thread sizes and fit differently-sized filter threads. If a fisheye lens adapter doesn't fit, install…
The base curve of the eye is the curve of the cornea over the iris and pupil. This curve matches the concave surface of the contact lens. The measurement is key for fitting hard contact lenses. Soft contact lenses do not require the same measurements since the lens material flexes and forms to the eye. Measuring the base curve of the eye requires special training and equipment. In most cases, your optometrist measures the base curve during your vision care visit. The wrong base curve will distort your vision and may injure your eye.
All contact lens fitting sessions start with an accurate refraction (prescription determination) and precise keratometry (corneal curvature) readings. Evaluate the patient's visual needs and determine which lenses are best for the patient. Clear and consistent vision is the goal of every contact lens fitting.
Progressive lenses must be accurately measured or fit because the progressive power placement is crucial for comfort and function. This type of lens provides a progression of power instead of only two or three lens power -- the way bifocal and trifocal lenses work. Progressive lenses are also called PALs, invisible or no-line bifocals. Measuring a PAL properly ensures the wearer will experience the best possible vision.
When you have an eye exam for contact lenses, your doctor performs several specialized tests above and beyond those administered during a routine eyeglass exam. Because of the additional tests, eye exams for contacts are usually more costly.
Contact lenses work in the same way as glasses do to correct vision. They redirect light that enters the eye so that it focuses correctly onto the retina. Many people prefer contacts to glasses because of the convenience of not carrying glasses around and because they believe they look better without glasses on. Contacts do require regular maintenance to keep them working properly. If your contacts don't fit correctly, mild or serious symptoms will likely result.
Eye movement training can be accomplished through a course of vision therapy. Vision therapy consists of a prescribed regimen of eye exercises that can be done at home or at an eye doctor's office.
Being fitted for monovision contact lenses can free you from the hassle of wearing reading glasses and bifocals or trifocals and can end the annoyance of eyeglasses slipping down the nose, being misplaced, or getting scratched. Visit your ophthalmologist or optometrist and have your eyes examined to determine if you are a candidate for monovision contact lenses. Monovision contacts provide you with one lens to correct nearsightedness and another lens for viewing objects in the distance.
The base curve is an important part of your contact lens and prescription. The curvature of the lens is determined by the size of your eye and is measured by your eye doctor during your contact lens fitting.
Contact lenses are designed to sit on the front of the eye, called the cornea. Each person's eyes have unique curves, and the lenses must be fit accurately to match the curve of each eye. Contact lenses are made from soft and rigid material and can be used to correct different types of vision problems or can be worn without a prescription to cosmetically change eye color. Precise measuring and rechecking of the fit of contact lenses is a must.
Toric contact lenses are soft contacts that help with astigmatism, a vision correction that involves the curvature of the outer layer of your eye, or cornea. Standard contacts only correct for distance or near problems, but toric contacts have additional power in a specific part of the lens that offset distortions caused by irregular curvatures of the eye. Toric lenses must be fit accurately to ensure the best vision.
Contact lenses are individually designed to fit on the front surface of the cornea, the clear outer membrane of the eye. An eye doctor verifies that lenses are fitting correctly after they have been worn for a period of time, usually one or two weeks. During a contact lens follow-up appointment, a slit lamp, also called a biomicroscope, is used to evaluate the fit of contact lenses.
Contact lenses possess a number of benefits over regular eyeglasses, but they can sometimes be uncomfortable to wear. In the worst cases, you should speak to your optometrist because glasses may be a better choice health-wise. But in most cases, you can make your contact lenses more comfortable by taking a few sensible steps in your everyday life. Most of the time, they boil down to simple maintenance, or being aware of your environment and making adjustments as appropriate.
The process of a contact lens fitting involves three steps: an interview to explain the fitting itself and to discuss your ocular history and lens options; a thorough eye exam; and the fitting of the lenses that have been determined as optimal for you. In the interview, you answer questions about your preferences and habits so that the optician has an idea of the most appropriate type of lenses (such as hard or soft lenses, daily wear or extended wear lenses) for you given your lifestyle. The interview also gives you the opportunity to ask your own questions about the…
Contact lenses are prescribed by an ophthalmologist to correct vision impairments and astigmatisms in one or both eyes. Astigmatism is the result of an oddly shaped cornea and can be present in a nearsighted or farsighted patient. Regardless of the type of vision impairment you wish to correct, soft and hard contact lenses can be a great solution for most people. Learn how you can lubricate the cornea and place the contact lens in your eyes for a comfortable fit.
Contact lenses are medical devices to correct vision that require a prescription from an eye care professional. A contact lens prescription not only contains the proper strength for correcting vision in each eye, it also includes the specific measurement needed to properly fit the curvature and diameter of one's eye. The correct measurements are determined during an eye exam and contact lens fitting session. A patient who has eyes that require specialized fitting can expect to pay more.
Vial contacts are lenses that are designed to be worn for up to a year. They must be removed daily, cleaned properly and stored in sterile solution. Vial contacts are available in soft or rigid (gas permeable) styles. Vial contacts can be used to correct a variety of vision problems including nearsightedness, farsightedness and astigmatism.
