Rigid contact lenses have many blends including color.
Rigid contact lenses replaced the hard, uncomfortable lens of the past. The new lens, known as rigid gas permeable, is made of plastic that is firmer than soft lenses. Rigid lenses produce a sharper vision and deliver oxygen to the cornea. People who have astigmatism and irregularities of the cornea find the rigid lens more suitable than soft lenses. Blends used in rigid contact lenses provide crisper vision and better aesthetics.
Corneal-Scleral Orthokeratology
The corneal-scleral orthokeratology lens is a rigid gas permeable that addresses the corneal curvature. The asymmetric blends are shorter toward the center and broadens towards the edges of the lens. It makes the lens fit to the cornea increasing the vision possibilities and correcting the curvature. A computer system can custom design a lens by measuring the sagittal height of the eye, a line measuring front to back.
Color Blends
Color blend lens attempt to mimic the natural eye color by blending various colors. The iris is usually a blend of more than one color, often in shades. Blending produces a more natural color. It is also used to enhance the eye's existing color. In some cases, multiple colors are blended together to make fanciful lenses that are used in movies. The rigid lens adapts well to the color and allows more patients to experience eye color change.
How can you tell if someone is wearing colored lenses-look at them from the side? You can often see the natural color of the iris from the side view. Color blend lenses are clear where the iris lies. One disadvantage to colored lenses is they slip when a person blinks causing the colored part to slide in front of the iris. A precaution for colored lens wearers it not to share lenses because it can cause infection and damage to the eye.
Bifocal
Bifocal or progressive lenses are a blend of two prescriptions without a visual line to distinguish them apart. People who suffer from presbyopia have difficulty seeing things close up such as a newspaper. Opting for contact lenses can eliminate the need for glasses. Bifocal or multifocal rigid lenses blend vision in two ways. The most common blend is the alternating vision where the pupil views through the two lenses with different prescriptions. An up or down view allows for close up vision and distance. The simultaneous lens blends the near and distance prescriptions that are viewed at the same time. Determining the proper lens view is not difficult for the eye to perform.
Tags: contact lenses, natural color, Color blend, from side, lenses blend, Rigid contact