Focus Night and Day contact lenses are made of silicone hydrogel – a combination of hydrogel, a soft plastic that contains water, and silicone, a compound which allows oxygen to pass through it. The combination of the two materials creates a lens capable of absorbing six times more oxygen than standard hyrogel lenses. Oxygen is crucial for optimum eye health.
The Focus Night and Day lens is flexible, stays moist, and is resistant to dehydration. Focus Night and Day lenses are beneficial in that they are durable, long lasting, comfortable, and easy to maintain. Also, the risk of infection is reduced, and not having to take the lenses out each night minimizes the hassle that some contact lens wearers experience.
Focus Night and Day contacts were the first lenses to be FDA (Food and Drug Administration) approved for continuous wear for 24 hours a day for as long as 30 days. Although the lenses are approved for use without removal for up to 30 days, this schedule may not suit all wearers. The length of wear is dependent upon the recommendation of one’s eye care practitioner.
During a year-long U.S. clinical study in which 1,300 eyes used Focus Night and Day lenses, 1,000 were able to complete the year of wear, and 67 percent wore the lens for a period of 22 to 30 days.
Focus Night and Day contact lenses do have some risks and side effects. As with any contact lens product, wearers are at risk of developing an eye infection; that risk increases for those who wear continuously, or for extended periods of time.
Another possible side effect of extended wear of Focus Night and Day contacts is cornea inflammation. Patients sometimes do not have symptoms, but those who do report redness, sensitivity to light, blurry vision and general discomfort.
A British study conducted at the University of Manchester in 2005 found that wearers who slept in standard hydrogel lenses were five times more likely to develop keratitis (corneal inflammation) than those who slept wearing silicone hydrogel lenses.
Some less serious side effects of extended wear of Focus Night and Day contact lenses include conjunctivitis or pink eye, eyelid irritation, dryness of the eye, and mild burning or stinging.
Anyone who experiences any discomfort or side effects should immediately contact their eye care practitioner.
Research firm Robert W. Baird & Co. projects that by 2009 silicone hydrogel lenses will make up more than two-thirds of contact lens sales in the United States.