Issues of eyeglasses and lenses

Thursday, November 19th, 2009 at 3:30 pm Post in Eyeglasses

Some people think that eyeglass wearing makes the wearer rely on them. In fact, eyeglass wearing causes no permanent visual change. Based on the misconception, those people are not willing to wear eyeglasses when they just feel good with the vision. But in sometimes, their actual vision is burry, thus bringing more risk when they are driving on the highway, especially at night.

People with high prescription may be bothered by conventionally thick eyeglass lenses. Currently, thinner lenses in materials of high-index and polycarbonate are available for those people. Combined with small, round frames, these lenses can always offer aesthetically satisfying appearance.

It is possible that the two eyes of one person have different problems. For instance, one eye is hyperopic and the other is myopic. In this case, aspheric and high-index eyeglass lenses can help, which can be equalized in thickness between the two eyes. Contact lenses can also help. On the market, different types of tints are provided to meet varying needs of kinds of people, such as shooters, golfers, tennis players, computer users and so on.

Most eye prescriptions from doctors are standard and worldwide acceptable. -2.00 -1.00 x 180 is a typical format of an eyeglass prescription. The first number indicates the degree of spherical refractive error. Positive numbers stand for farsightedness and negative ones mean nearsightedness. The second number signifies astigmatism. In case of no astigmatism, DS or SPH can be a replacement. The final number varying from 1 to 180 shows the orientation of the football shape in astigmatic patients.

Eyeglass lenses can be applied with types of coatings. Anti-reflective coating minimizes reflections by preventing light from bouncing between the two lens surfaces. Polarization is another lens technology that can reduce glare from external objects such as water, car hood or a shiny road.

In eye care lingo, there are fixation disparities. With these problems, the eyes tend to try and pull apart, causing muscle imbalances. Prism in lenses can be prescribed to provide help in easing these imbalances. Well-prescribed prism can help the wearer use his eyes together. In addition, prism is also considered to help with double vision by aligning the two images into one.