Researchers are developing contact lenses that darken automatically in sunlight, similar to photochromic lenses available for prescription glasses. The contacts are treated with sun-sensitive dyes that darken when exposed to ultraviolet light, which is harmful to eyes.

Earlier attempts to make photochromic contacts were few and unsuccessful. Now, researchers at the Institute of Bioengineering and Nanotechnology (IBN) in Singapore are making headway by using a contact lens material that contains a network of nano-sized tunnels that can be filled with photosensitive dyes. The structure of the flexible lens material allows the dye to react quickly and uniformly throughout the lens, according to the researchers.

Edwin Chow, IBN senior research scientist, says this technology has a faster response time than photochromic eyeglass lenses (such as Transitions lenses) currently on the market. While photochromic lenses can take minutes to fully react to light, the new photochromic contacts can respond in 10 to 20 seconds, he says.

Next the research team will test the contact lenses in animals. IBN Director Jackie Ying believes the contacts could be available commercially outside the United States within a year. Approval for use in the U.S. may take longer due to safety testing required by the Food and Drug Administration (FDA).

The study was reported this month in Technology Review, published by the Massachusetts Institute of Technology (MIT).

“Can my child successfully wear contact lenses?”

It’s a question many parents ask their eye doctor when their kids want contacts. In this month’s Contact Lens Spectrum, Jeffrey Walline, OD, PhD, and Marjorie Rah, OD, PhD, discuss some of the factors associated with the success (or lack of success) children have when attempting to wear contact lenses.

Recent research suggests that more than 90 percent of children ages 8 to 14 can successfully adapt to wearing soft contact lenses. Because of this high success rate, most children who are interested in contact lenses choose soft lenses.

With gas permeable contact lenses (also called GP contacts), it’s a different story. The success rate fitting children with GP lenses is approximately 55 percent. For this reason, Drs. Walline and Rah say more careful screening of candidates for these lenses may be beneficial.

In a study published in 2009, Dr. Walline found that most children who were unable to adapt to contact lens wear tend to stop wearing the lenses within the first few weeks. But is was unclear to the researchers if these children simply chose not to wear the GP lenses frequently enough and long enough to adapt to them, or if contact lens discomfort or other factors made adapting to the lenses impossible, and this was the reason they wore the lenses less than those who were successful.

From their personal experience fitting children with contacts, the authors have found that children who are squeamish about having their eyes or eyelids touched by their doctor during an eye exam are less likely to succeed with contact lens wear. Children with small eye openings, poor dexterity or poor hygiene also are less likely to wear contacts successfully.

Parents also are a factor in a child’s success wearing contacts, according to the doctors. Parents who are involved without being overbearing offer the best support environment for their kids to wear contacts successfully, they say.

Dr. Walline is an assistant professor at Ohio State University College of Optometry, where he conducts studies of pediatric contact lens wear. Dr. Rah is a staff optometrist at the Massachusetts Eye and Ear Infirmary Contact Lens Service, where she specializes in medically necessary contact lenses and advanced contact lens designs.

In this month’s issue of Contact Lens Spectrum, editor and contact lens specialist Jason J. Nichols, OD, warns that current economic conditions may be affecting how people are wearing and caring for their contact lenses.

Dr. Nichols says hard economic times can alter people’s behavior regarding their health, including how frequently they replace their contacts and how they use contact lens solutions.

“I am hearing more and more reports of patients looking for the cheapest ‘bottle’ on the shelf, which just happens to be saline rather than an appropriate care solution,” he says. Many contact lens wearers may also be using their lenses for longer periods of time rather than discarding and replacing them according to the schedule their optometrist or ophthalmologist recommends, according to Dr. Nichols.

Internet blogs and social networking sites may be contributing to the problem: some sites feature discussion boards where contact lens wearers report how they routinely wear their disposable contacts longer than recommended.

Dr. Nichols warns that poor contact lens habits frequently lead to contact lens-related eye infections, including severe infections like Acanthamoeba keratitis. He urges eye doctors to continue educating and re-educating their patients about proper contact lens wear and care.

In a related story published in the journal, a survey released by the American Optometric Association indicates 52 percent of consumers are visiting their eye doctor less frequently due to economic reasons. The same survey says 59 percent are visiting their primary care physician less frequently.

A study published in a recent issue of Eye & Contact Lens indicates that children ages 8 to 12 are able to successfully wear daily disposable contacts and that most children in the study preferred wearing contact lenses to wearing eyeglasses.

The three-month study was conducted in Singapore, following a protocol similar to the recent Contact Lenses in Pediatrics (CLIP) study in the United States that found similar results among teenagers.

Participants in the study were fit with 1-Day Acuvue and 1-Day Acuvue for Astigmatism disposable contacts. All children were nearsighted (with or without astigmatism) and had not worn contact lenses prior to the study.

Of the 59 children enrolled, 53 (90 percent) completed the study successfully. At the end of the three-month study period, most of the children and their parents reported preferring the contact lenses to eyeglasses for a variety of reasons, including vision, comfort and appearance.

No eye infections occurred during the study, and the only adverse event noted was the development of a chalazion in one child’s eyelid.

(Many eye doctors recommend daily disposable contacts for children who want to wear contact lenses because the single-use lenses eliminate the need for daily lens care and contact lens solutions.)

Eye & Contact Lens is the official journal of the Contact Lens Association of Ophthalmologists.