Glare
Decreased visual perception related to glare is a frequent complaint. As the eye ages, changes in the lens and vitreous increase the scattering of light in the ocular media. Lens opacities at the periphery, though not directly interfering with vision, can also increase the scattering of light passing through the lens, especially at night or in dim light, because the pupil is slightly dilated. Thus, it is not unusual for the elderly patient to complain about the glare of oncoming headlights while driving at night. As long as visual acuity is normal, the patient should just be advised to curtail driving at night or avoid looking directly at oncoming headlights.
Decreased visual perception from daytime glare is also common. With aging, opacities may appear in various portions of the lens, such as the nucleus and cortex. Such opacities may interfere little with visual acuity, but opacities in the central cortex region just beneath the posterior lens capsule (posterior subcapsular lens opacities) tend to scatter light to a greater extent. This occurs because these opacities are closer to the focal point of the lens through which all light must pass on the way to the retina. Although these opacities may eventually increase in size or density and interfere with visual acuity (posterior subcapsular cataract), their earliest manifestation is the scattering of light and increased glare, especially in bright light.
Some temporary relief may result from mild dilation of the pupil with mydriatic drops and from sunglasses that allow the patient to see around the opacity. However, these measures should be used only under appropriate ophthalmologic care. Early nuclear opacities may actually improve close vision in the elderly. Cataracts are discussed further below.

Glare
Decreased visual perception related to glare is a frequent complaint. As the eye ages, changes in the lens and vitreous increase the scattering of light in the ocular media. Lens opacities at the periphery, though not directly interfering with vision, can also increase the scattering of light passing through the lens, especially at night or in dim light, because the pupil is slightly dilated. Thus, it is not unusual for the elderly patient to complain about the glare of oncoming headlights while driving at night. As long as visual acuity is normal, the patient should just be advised to curtail driving at night or avoid looking directly at oncoming headlights.
Decreased visual perception from daytime glare is also common. With aging, opacities may appear in various portions of the lens, such as the nucleus and cortex. Such opacities may interfere little with visual acuity, but opacities in the central cortex region just beneath the posterior lens capsule (posterior subcapsular lens opacities) tend to scatter light to a greater extent. This occurs because these opacities are closer to the focal point of the lens through which all light must pass on the way to the retina. Although these opacities may eventually increase in size or density and interfere with visual acuity (posterior subcapsular cataract), their earliest manifestation is the scattering of light and increased glare, especially in bright light.
Some temporary relief may result from mild dilation of the pupil with mydriatic drops and from sunglasses that allow the patient to see around the opacity. However, these measures should be used only under appropriate ophthalmologic care. Early nuclear opacities may actually improve close vision in the elderly. Cataracts are discussed further below.
Haziness, Flashing Lights, and Moving Spots
Decreased visual perception due to opacities in the ocular media are most often attributed to vitreous floaters or to Moore’s lightning streaks. The vitreous humor is a gelatinous-like material that fills the back of the eye between the posterior surface of the lens and the anterior surface of the retina. The vitreous is normally clear, but with age, discrete opacities or structural changes leading to a general haziness may develop. With an ophthalmoscope, an examiner may be able to distinguish between lens opacities (best seen with a + 10 lens) and vitreous opacities (best seen with a +2 lens). Although these changes are not serious, they may upset the patient, and an explanation and reassurance are necessary.
The vitreous is firmly attached to the most anterior peripheral portion of the retina and posteriorly at the optic nerve. With age, the vitreous undergoes liquefaction, and as a result, eye movements produce intermittent tension at the vitreous attachment to the retina. This tugging stimulates the peripheral retina mechanically, causing vertically oriented flashing lights, almost always in the far temporal visual field. Unlike the aura in migraine, these flashing lights occur in only one eye at a time. If they are not accompanied by decreased vision or other changes in visual function, they usually need no further evaluation. However, if they persist and the feeling of a veil over the eye or a decrease in the visual field occurs, the patient should be referred immediately for an ophthalmologic examination to exclude retinal detachment.
In nearsighted (myopic) patients and in many others in their late 50s and early 60s, opacities appear as lines, spots, webs, and clusters of dots moving slowly across the field of vision. Usually, they move more rapidly with eye movements and become stationary when the eye is not moving. These opacities represent bits of vitreous that have coalesced or vitreous that has broken off from its attachment to the peripheral or central portion of the retina and now floats freely in the vitreous cavity (floaters). Floaters may also occur in uveitis. This symptom is annoying but usually has no clinical importance. If, after appropriate examination, the patient is reassured and encouraged to ignore the floaters, they gradually become less noticeable. However, a shower of opacities, often accompanied by flashing lights in the peripheral visual field, requires a referral to rule out retinal detachment.
Refractive Changes
Presbyopia, loss of accommodation, is a universal age-related change in lens physiology beginning in the 50s. When a person wishes to see an object closer than 1 or 2 ft (Vs to % m), the lens must increase its thickness to provide additional refractive power to focus the light from the near object on the retina. With presbyopia, the lens cannot make this accommodation.
If a person is farsighted (hyperopic), presbyopia tends to occur at an earlier age. Usually, a nearsighted (myopic) person with presbyopia can read small print by removing the glasses and holding the print close.
Presbyopia is corrected in both nearsighted and farsighted persons with either separate reading glasses or bifocal glasses. Since accommodation is lost progressively from about ages 45 to 65, the reading lens must be changed every 2 or 3 yr. Refractive changes resulting from cataracts are discussed below.