disposible contact lenses

Are you in the market for some new contacts? Are you looking for quality contacts by Biomedics? Check us out. We have a comprehensive selection of contacts by all the major manufacturers including Biomedics. - Find here

An added benefit is that soft lenses aren''t as likely as rigid lenses to pop out or capture foreign material like dust underneath. Extra-thin soft lenses are available for very sensitive people. While the ability to hold water increases oxygen permeability of soft lenses, it increases their fragility as well. Rigid lenses generally give clearer vision. They can be marked to show which lens is for which eye. They don''t rip or tear, so they''re easy to handle. Also, rigid lenses don''t absorb chemicals, unlike soft lenses, which are like sponges. They''ll suck up any residues on your hands--soap, lotion, whatever. Both soft and rigid lenses offer bifocal correction. In some models, each lens corrects for near and distance vision. In others, one lens is for near vision, and the other is for distance. Middle-aged people who have good distance vision but need help for reading can get a monovision reading lens for one eye.

The disposible cornea consumes oxygen and produces carbon dioxide at rates proportionate with free diffusion of gases in air. The corneal epithelium requires a minimum p02 of 15 mmHg for proper aerobic glucose metabolism. Since available atmospheric oxygen is carried in the precorneal tear film, any lens material incapable of transmitting oxygen may lead to corneal haziness and corneal necrosis. Keeping the eyes closed or wearing Lenses lowers the p02 from normal contact to 32 mmHg to 9 mmHg. The availability of oxygen to the cornea can be determined by monitoring the lactate concentration in the cornea. For the cornea to maintain its functional integrity, the lens must be able to slide and move over the corneal surface with each blink so as to allow oxygen permeation. This oxygenation process in hard contact lens wearers is often referred to as "tear pump phenomenon" whereby the corneal epithelium is provided with oxygen-coated tears.

Soft lenses. Soft Lenses have become the most popular among all the types of lenses. They contain hydroxyl or hydroxyl and lactam groups, which allow them to absorb and hold water. A majority of soft lenses are composed of 2-hydroxyethylmethacrylate (HE MA) with small amounts of cross-linking agents that provide a hydrogel network. The extent of cross-linking determines the hydrophilicity of the lens; lenses any increase in the extent of cross-linking results in a decrease in availability of hydrophilic groups for interaction with water, causing the lens to be less flexible and less hydrated. Hydrophilic lenses tend to accumulate more protein deposits than hydrophobic lenses. Daily-wear contacts need to be removed before the wearer goes to sleep at night, while the extended-wear contacts may be worn more than a day, with some having been approved for continuous use for up to disposible a month.

Are you in the market for some new contacts? Are you looking for quality contacts by Biomedics? Check us out. We have a comprehensive selection of contacts by all the major manufacturers including Biomedics.