Biomedics 55 Premier contacts from Coopervision are designed to provide comfort, highly functioning visual acuity and good ocular health to the planned replacement soft lens wearer. These lenses are designed to address the problems of compromised visual perception by virtually eliminating spherical abberation.
Spherical abberation is an optical effect observed when light rays are refracted back toward the optical center of the lens causing distortion. A spherical contact has an aplanatic point. This is the optical center of the lens where there is the least amount of deviation from the prescription. The area of lens effectively utilized can be calculated mathematically by taking the radius of the aplanatic point and dividing it by the refractive index of the contact. Since contacts rest directly on the cornea, the vertex distance, which is the distance between the optical device, i.e. the contact and the eye, is minimal. Therefore, spherical aberration is reduced.
However, this does not eliminate it entirely especially in instances of low light situations. The pupil will dilate in response to low lighting situations so vision will be improved. When this dilation occurs the peripheral edges of the optical zone of the contact will become more apparent causing some degree of spherical abberation.
Biomedics 55 Premier contacts are designed to nearly eliminate this problem through an aspheric design. Simply put, the lens maintains the same radius of curvature over a wider area, therefore reducing the effects of this abberation and improving visual acuity. Since the lens is aspheric in design, it providers a wider optical zone and field of view for the patient as well as better transmittance of light allowing crisp, clear vision.
In addition to its unique aspheric design, Biomedics 55 Premier also prevent nearly 100% of harmful UV rays bombarding ocular tissues. The absorption of ultraviolet radiation has been linked to the development of cataracts, macular degeneration and various forms of cancer which can also occur inside the globe of the eye. Ocular tissues will undergo cellular changes such as in the case of the crystalline lens. If there is a substantial amount of UV absorption in the crystalline lens the nulcear proteins found there will breakdown and cause the lens to become cloudy and eventually opaque.
This is known as a cataract. Maintaining good ocular health should always include limiting the amount of the eye’s exposure to UV rays. Biomedics 55 Premier contacts provide this protection, but it should be noted this will not protect the surround ocular tissues since the area of the contact is limited to the cornea and a small amount of sclera. Sunglasses with adequate UV protection should always be worn to protect the area around the eye as well.
Biomedics 55 Premier contacts are comprised of a combination of polymers including ocufilcon D which is a hydrophilic, water-loving, hydrogel designed to retain moisture and maintain the fluid environment necessary for a healthy corneal tear film. This translates to better comfort, healthier eyes and better visual performance.