Astigmatism causes objects to be blurred both at a distance and up close. Your eye doctor can prescribe lenses to ensure your vision is clear.
Presbyopia occurs due to a loss of the flexibility of the lens inside the eye. This is a normal aging process within your visual system. As the lens ages, it loses its elasticity which allows it to change shape and focus on items up close. Presbyopia is first noticed when individuals reach their mid-forties.
If you are in your mid-forties and are having a difficult time reading items up close, you may have presbyopia. Many times people will complain that their arms are too short or they have to hold item at arms length to read them. People with presbyopia notice that objects become clearer as they are moved away from their face.
First, realize that presbyopia is due to normal aging changes. Second, you should have an optometric examination that analyzes your up close/near vision for presbyopia. If diagnosed with presbyopia, you will be prescribed reading glasses or bifocals.
A certain amount of light that enters a lens will be reflected back upon itself. An anti-reflective (AR) coating eliminates these unwanted reflections and ghost images. If you are bothered by fluorescent lights or oncoming headlights at night this coating may be beneficial to you. Cosmetically this is also a good choice.
A polarized lens blocks the transmission of light in one axis/plane while allowing the light 90 degrees away to pass through that lens. Light that is reflected off a surface becomes polarized for example light reflected from water on a lake. Polarized lenses eliminate this annoying reflective light.
Refractive surgery is a surgical procedure which alters the refractive qualities of the eye. The most common refractive surgery is Laser in Situ Keratomileusis or more commonly known as LASIK. LASIK reshapes the cornea of the eye to negate myopia, hyperopia, or astigmatism. LASIK will not heal amblyopia (lazy eye) or presbyopia (the normal loss of accommodation from aging). To be a candidate for LASIK, you must 1) be at least 21 years of age, 2) have healthy eyes, 3) have good general health, and 4) have a stable glasses prescription for over one year. LASIK surgery is usually performed as an outpatient procedure using a topical anesthetic to numb the eye. There are three major steps during the LASIK surgery. First, a surgical blade slices a flap on the top portion of the cornea exposing the inner layers of the cornea. Second, a specialized excimer laser removes corneal tissue until the proper prescription is achieved. Third, the corneal flap is placed back over the exposed inner layers of the cornea. Usually the patient will see better without glasses immediately after surgery or within a day or two.
Actually eye dilation refers to the pupil of the eye being dilated. The pupil is the dark area in the center of the iris (the blue, green, or brown part of the eye). The pupil is a window that allows light into the eye to be detected by the retina. In dim light the iris pulls outward enlarging or dilating the pupil so more light gets to the retina. When the light is bright or a light is shined on the eye, the iris pulls inward shrinking or constricting the pupil so the retina is not over exposed. The eye doctor uses drops to control the iris muscles so the natural reflex to constrict in bright light is temporarily blocked.
With pupil dilation the doctor can use light (its not really that bright it just feels that way) to see the structures on the inside of the eye. A much greater portion of the arteries, veins and retinal tissue can be observed with greater precision. Therefore, pupil dilation is recommended as a routine part of comprehensive eye examinations. Patients with certain risk factors such as diabetes, high amounts of nearsightedness, and other factors may need to have their eyes dilated more often.
When your eyes are dilated, most people will notice some sensitivity to light, slight glare, and blurring of near vision. In addition, some people may notice problems with driving. Usually these side effects of the dilation will return to normal within four to six hours. For your eye appointment, you may want to consider having another person drive you home. To reduce the problems associated with the eye dilation, please bring along some sunglasses. If you do not have sunglasses, some disposable sunglasses will be provided. If you wear contact lenses, bring your backup glasses; you may not be able to wear your contact lenses until the eye drops have worn off.
Undilated Eye versus Dilated Eye