Most people notice presbyopia at around 40 years old. Individuals suffering from this eye condition usually have some signs or symptoms. They always hold things such as handwritten items, sewing and newspapers at a length’s distance. Only in this way can they see these objects clearly. Presbyopic people also have difficulty reading in poor light conditions. It is also hard for them to see small detail or print. Serious cases include headaches or tired eyes after long-time reading.

Natural aging is exactly the cause of presbyopia. The natural lens of the eye continues to develop and young adults always have great lens flexibility. However, this flexibility gradually decreases as people age. As a result, a person reaching a certain age needs prescription lens for detail reading. This process is inevitable for everyone.

Reading glasses are widely used for those presbyopic people without a distance prescription. These glasses perform well in close materials reading. Reading glasses come in ready-made and custom-made types. It is quite necessary to get a right prescription when a person wants to buy ready-made reading glasses.

Reading glasses have a shortcoming that they can only help in close reading. What’s worse, this type of glasses usually causes blurry vision in distance objects. In this consideration, varifocal lenses are created to meet one’s needs for both far and near vision. Varifocal lenses provide three powers within a lens. With this kind of lenses, wearers are allowed to properly focus on everything at distance, middle distance or close up.

Another type of multifunctional glasses is bifocals, which have both a reading and distance prescription. Bifocal glasses are incompetent for computer work, because they do not have a middle distance prescription. In similar, dashboard in the car is also beyond bifocal lenses.

Multifocal contact lenses in various types are also helpful in addressing presbyopia. Contact lenses can be combined with monovision.

more info

·Brief introduction of presbyopia

·Differences between hyperopia and presbyopia

·Presbyopia causes and treatments

However, there are some people who have both of the two vision problems. They need vision correction of both distance and near objects. Of course, these single vision eyeglasses are incompetent. Only bifocal eyeglasses can provide the needs for such a group of people. A bifocal lens has two lenses, one for myopia correction and the other for hyperopia correction. To wit, there are actually four lenses in a pair of bifocal eyeglasses.

Most people will need bifocal glasses only when they become older. At early ages, single vision eyeglasses are enough. Bifocal lenses can always reduce eye strain in early stages. Customers should make a consultation with an optometrist before choosing bifocal eyeglasses, because there are various styles of bifocals now.

Bifocal lenses in an old design have a visible line in each lens, which brings an unnatural look. Modern progressive lenses effectively remove the line. They provide clear vision irrespective what and where the object is. There is no line that will affect visual perception. While ensuring normal visual correction of both nearsightedness and farsightedness, progressive lenses appear more naturally.

The modern design of a bifocal lens is that the lower portion for closer objects and the upper part for distance vision. The reason for this design is that people always put their heads slightly down when they try to read and write.

However, customers will always get unsatisfied if they expect bifocal eyeglasses to deal with all situations. When it comes to computer use, the common bifocal design is not suitable, because the computer monitor is directly in front of the lenses.

In some cases, bifocal contact lenses are better than bifocal eyeglasses. People wearing bifocal contacts never need to move their heads in order to see through the proper part of the lenses. Moreover, contact lenses offer wider peripheral vision.

moro info

·Advantages and types of progressive lenses

·Ordinary and occupational multifocal lenses

A bifocal lens of Benjamin’s style has two different parts: the upper half for distance vision and the bottom half for near vision. This is the most natural design that people are accustomed to look up to see distant things and look downward to perceive close-up objects. There are other designs of bifocal lenses that have different shapes or sizes of each prescription parts. But this basic concept has never been changed.

Presbyopic folks can benefit most from bifocal glasses. This eye condition is different from farsightedness, which is a common misconception. An obvious sign of presbyopia is the inability to focus on near things such as newspapers, books and so forth. Presbyopia is very common among people in their middle ages. It is estimated that approximately 4 million Americans develop this eye problem every year. And diabetic patients have a double rate of getting presbyopia.

Presbyopia can not be stopped that it will slowly corrode the falling years of the patients. Although total or permanent blindness is rare, presbyopia can interfere in one’s daily life. In this case, vision correction is quite necessary for presbyopic patients. Bifocal glasses are the most appropriate solution.

Individuals who use bifocal glasses for the first time may need a period of adjustment. At the very beginning, the things through the lower part appear closer than they really are. In serious cases, some new users even report a headache or tired eyes. After several days, the eyes can adapt to different prescriptions in a lens and the vision correction at both distances will be comfortable.

Extended reading

·Presbyopia causes and treatments

·Brief introduction of presbyopia

After the invention of bifocal reading glasses, this kind of switch is eliminated. Bothered by the inconvenience and time-consuming factors of separate pairs of eyeglasses, the American statesman Benjamin Franklin cut his two lenses in half and fitted them one above the other. In this way, originally simple bifocal lenses were invented, which could provide both close and distance vision. After that, there have been a variety of mutations of this invention. The bifocal eyeglasses had saved Benjamin Franklin a lot of time, which was quite important for a busy man of his kind.

In standard styles, the top half of a bifocal lens is designed for visibility at a distance and the bottom section for materials reading. This design is natural because most people look down while reading and up while focusing at the distance.

Bifocal lenses with a Franklin’s style have a distinct line separating the two parts, and sometimes they are called Executive lenses. This is the most primary bifocal lens design. Currently, there are still other designs of bifocals. Progressive lenses remove the visible line in the lens, making bifocal lenses more natural. Yet there are also different shapes of the reading zone in the bottom section of the lens. A design of bifocal lenses is a round part for near vision, while some other bifocal lenses are equipped with a slanted ‘D’ or half-moon shape for close vision.

Although bifocal lenses may require a period of adaption in some people, the most beneficial advantage is that they can help wearers get rid of lens switches between separate pairs of eyeglasses.

References

·Ordinary and occupational multifocal lenses

·What are bifocals and bifocal contacts?

·Advantages and types of progressive lenses

Presbyopia is to some content inevitable in people above 40, which causes individuals difficult in managing up close tasks. As people grow older, presbyopia also advances. As presbyopia develops, people may be forced to keep more than one pair of eyeglasses or change glasses with a higher prescription. Solutions to presbyopia include reading glasses, multifocal contact lenses or eyeglasses, monovision LASIK and conductive keratoplasty.

About half of all 65-year-old Americans suffer some degree of cataracts, and the number of cataract patients will reach 30 million by 2020. There are so large a number of cataracts cases that this eye disease has been considered as a normal ageing change. Cataract surgery is the most widely applied treatment, which removes cloudy cataracts on the lens. Multifocal lens implants during a cataract surgery can restore vision at all distances.

Common age-related eye diseases include macular degeneration, glaucoma and diabetic retinopathy. Age-related macular degeneration has been the leading cause of blindness in American seniors. People in their 80s develop glaucoma at a 12 percentage. The National Eye Institute estimates that 40% of the 10.2 million of diagnosed diabetic patients have some degree of diabetic retinopathy.

Natural aging involves various subtle changes in vision and eye structures, including pupil size, tears production, peripheral and color vision, vitreous and so on.

The pupil becomes smaller and less responsive to changes in ambient lighting as people age. As a result, older individuals always need more ambient light for comfortable reading. They may get help from photochromic lenses or lenses with anti-reflective coatings. Aging also makes the eyes to generate fewer tears, especially in women after menopause. Artificial tears can be prescribed to ease symptoms such as burning and stinging caused resulted from dry eye.

Older people also suffer peripheral vision loss, which is quite harmful during driving. Older motorists need more attention when approaching intersections. Color vision and color sensitivity declines are also quite common in old people, which result from the aging of related retinal cells that are responsible for color perception. Unfortunately, there is no effective treatment for decreased color vision. Aging may bring vitreous detachment, resulting in spots and floaters as well as flashes in the visual field. These symptoms may signify a detached retina that is likely to cause blindness.

Treatments of age-related vision changes involve some other factors. eye exams from professional optometrists or ophthalmologists are important to detect vision problems. And old people should tell their doctors about family vision history, current taking medications and other conditions that may be associated with vision health. Eye health also requires a healthy diet and smoking quitting.