Presbyopia is physiological insufficiency of accommodation associated with the aging of the eye that results in progressively worsening ability to focus clearly on close objects. Also known as age-related farsightedness (or age-related long sight in the UK), it affects many adults over the age of 40. A common sign of presbyopia is difficulty reading small print which results in having to hold reading material farther away. Other symptoms associated can be headaches and eyestrain. Different people will have different degrees of problems. Other types of refractive errors may exist at the same time as presbyopia. This condition is similar to hypermetropia or far-sightedness which starts in childhood and exhibits similar symptoms of blur in the vision for close objects. Presbyopia is a typical part of the aging process. It occurs due to age related changes in the lens (decreased elasticity and increased hardness) and ciliary muscle (decreased strength and ability to move the lens), causing the eye to focus right behind rather than on the retina when looking at close objects. It is a type of refractive error along with nearsightedness, farsightedness, and astigmatism. Diagnosis is by an eye examination.Presbyopia can be corrected using glasses, contact lenses, multifocal intraocular lenses, or LASIK (presbyLASIK) surgery. The most common treatment is glass correction using appropriate convex lens. Glasses used to correct presbyopia may be simple reading glasses, bifocals, trifocals, or progressive lens.People over 40 are at risk for developing presbyopia and all people become affected to some degree.
Image capturing in the eye
Solutions for presbyopia have advanced significantly in recent years due to widened availability of optometry care and over-the-counter vision correction options. Corrective lenses
Corrective lenses provide vision correction over a range as high as +4.0 diopters. People with presbyopia require a convex lens for reading glasses; specialized preparations of convex lenses usually require the services of an optometrist.Contact lenses can also be used to correct the focusing loss that comes along with presbyopia. Multifocal contact lenses can be used to correct vision for both the near and the far. Some people choose contact lenses to correct one eye for near and one eye for far with a method called monovision. Surgery
Refractive surgery has been done to create multifocal corneas. PresbyLASIK, a type of multifocal corneal ablation LASIK procedure may be used to correct presbyopia. Results are, however, more variable and some people have a decrease in visual acuity. Concerns with refractive surgeries for presbyopia include peoples eyes changing with time. Other side effects of multifocal corneal ablation include postoperative glare, halos, ghost images, and monocular diplopia. Image processing in the brain
A number of studies have claimed improvements in near visual acuity by the use of training protocols based on perceptual learning and requiring the detection of briefly presented low-contrast Gabor stimuli; study participants with presbyopia were enabled to read smaller font sizes and to increase their reading speed. Eye drops
Pilocarpine, eye drops that constrict the pupil, has been approved by the FDA for presbyopia. Research on other drugs is in progress.