presbyopia presbyopia 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. presbyopiaother namesthe aging eye conditiona person with presbyopia cannot easily read the small print of an ingredients list (top) compared to someone without presbyopia (bottom).specialtyoptometry, ophthalmologysymptomsdifficulty reading small print, having to hold reading material farther away, headaches, eyestrainusual onsetprogressively worsening in those over 40 years oldcausesaging-related hardening of the lens of the eyediagnostic methodeye examtreatmenteyeglasses, contact lensesfrequency25% currently; all eventually affected 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. around 25% of people (1.8 billion globally) are currently affected. signs and symptoms the first symptoms most people notice are difficulty reading fine print, particularly in low light conditions, eyestrain when reading for long periods, blurring of near objects or temporarily blurred vision when changing the viewing distance. many extreme presbyopes complain that their arms have become "too short" to hold reading material at a comfortable distance. presbyopia, like other focal imperfections, becomes less noticeable in bright sunlight when the pupil becomes smaller. as with any lens, increasing the focal ratio of the lens increases depth of field by reducing the level of blur of out-of-focus objects (compare the effect of aperture on depth of field in photography). the onset of presbyopia varies among those with certain professions and those with miotic pupils. in particular, farmers and homemakers seek correction later, whereas service workers and construction workers seek correction earlier. scuba divers with interest in underwater photography may notice presbyopic changes while diving before they recognize the symptoms in their normal routines due to the near focus in low light conditions. interaction with myopia people with low near-sightedness can read comfortably without eyeglasses or contact lenses even after age forty, but higher myopes might require two pairs of glasses (one for distance, one for near), bifocal, or progressive lenses. however, their myopia does not disappear and the long-distance visual challenges remain. myopes considering refractive surgery are advised that surgically correcting their nearsightedness may be a disadvantage after age forty, when the eyes become presbyopic and lose their ability to accommodate or change focus, because they will then need to use glasses for reading. myopes with low astigmatism find near vision better, though not perfect, without glasses or contact lenses when presbyopia sets in, but the more astigmatism, the poorer the uncorrected near vision. a surgical technique offered is to create a "reading eye" and a "distance vision eye", a technique commonly used in contact lens practice, known as monovision. monovision can be created with contact lenses, so candidates for this procedure can determine if they are prepared to have their corneas reshaped by surgery to cause this effect permanently. mechanism