You may benefit from high-definition eyeglass lenses if you wear eyeglasses that fully correct your vision but you still feel unhappy about how you see. Sometimes higher-order irregularities can affect your vision, even if your prescription eyeglasses correct the main cause of your vision problem. These irregularities can be caused by the optical characteristics of your eyes or by the optical limitations of traditional eyeglass lenses.
High-definition eyeglass lenses can correct optical irregularities and have the potential to give you sharper vision than you’ve ever had before.
High-definition lenses can provide:
- sharper image quality in all lighting conditions
- better peripheral vision
- improved contrast sensitivity
- less glare at night
High-definition lenses are also available in high-index and progressive lenses. The most popular type of high-definition lenses are called free-form, which refers to an advanced manufacturing process that reduces higher-order irregularities such as spherical irregularities that occur in eyeglass lenses made in the traditional way.
Free-form lenses are made using your eyeglass prescription, which is then optimized with computer-controlled surfacing equipment that’s much more precise than conventional tools.
The making of some digital free-form lenses also takes into account how the lenses are positioned in front of your eyes in the eyeglass frames. This produces the most accurate lens power and the sharpest vision possible.
Lens Customization Factors
The lens customization process includes other factors, such as the angle between the eye and the back surface of the lens in different gaze points, for instance if you are looking off to the side rather than straight through the lens center. The frame size and the position of your pupil within the frame outline are other factors to consider in the customization process.
Taking these and perhaps other factors into account during the design and manufacture of the lens, offers an exceptional degree of customization that may reduce or even eliminate certain higher-order irregularities.
The personalized surfaces of high-definition lenses can help to reduce irregularities that limit your field of vision and cause starbursts, halos and comet-shaped distortions of lights at night.
Additional Measurements Needed
Creating high-definition lenses requires additional information beyond what is on your eyeglass prescription, so your optician will usually take additional measurements when you choose your new eyeglass frames. Sometimes a branded measuring device is used for fitting and making a specific brand of free-form, high-definition lenses.
An even more customized type of high-definition eyeglass lens is called wavefront. Wavefront lenses are made with the help of the same sophisticated technology used to measure the optics of the eye before custom, wavefront-guided LASIK eye surgery.
Wavefront is a computerized instrument that projects uniform light waves into the eye that reflect off the retina. The returning “wavefront” of light is analyzed to evaluate all optical imperfections, including higher-order irregularities.
When making wavefront eyeglass lenses, these measurements are used in a computer-controlled manufacturing process to create customized, high-definition lenses.