Astigmatism occurs when the cornea, the clear, dome-shaped tissue that covers the front of the eyeball is more oval or egg shaped like a football instead of round like a basketball. This creates two focal points instead of one. As a result, light rays entering the eye are focused to a blurry spot rather than a sharp point on the retina in the back of the eye.
Farsightedness, or hyperopia, is the condition in which the eye focuses on distant objects better than on objects closer to the eye. The focal point in hyperopia is beyond the horizon so nearby objects appear very blurry, but in severe cases even distance vision can be somewhat distorted. This happens when light rays refract, or bend, incorrectly in the eye. The eye is designed to focus images directly on the surface of the retina; when the cornea is incorrectly curved, light rays focus behind the surface of the retina, producing a blurry image.
Hyperopia can be treated in a variety of ways. The most common is a pair of reading glasses or contact lenses. Hyperopia can also be treated with invasive or non-invasive medical procedures, including the laser surgeries PRK (photorefractive keratectomy), LASIK (laser-assisted in situ keratomileusis), and cataract surgery.
Nearsightedness, or myopia, is a vision condition in which nearby objects are clear and distant objects appear blurry. This may be caused by excess corneal curvature or an eye that is longer than normal , both of which affect the way light is bent upon entering the eye and whether it focuses properly on the retina. In myopia, the light rays are focused in front of the retina.
Eyeglasses and contact lenses are common methods of correcting nearsightedness. Eyewear may be used for certain activities, like watching television or driving, or for all activities. Alternately, vision correction procedures such as LASIK, PRK, and even cataract surgery are highly effective at treating this condition.
Presbyopia is a natural change in our eyes’ ability to focus. It occurs when the soft crystalline lens of the eye loses flexibility and starts to harden. This loss of flexibility affects the lens’ ability to focus light in the eye, causing nearby objects to look blurry. Presbyopia happens to everyone starting in our 40s or 50s – even in patients who have had laser vision correction.
The effects of presbyopia can be corrected with glasses or contact lenses, including bifocals and multifocals; multifocal lens implantation, including Crystalens™, ReZoom® and ReSTOR®; and monovision refractive surgery. Laser surgeries such as LASIK and PRK cannot correct presbyopia because they reshape the cornea rather than treat the lens unless a monovision treatment is performed.
Dry eye occurs when the eyes are not sufficiently moisturized. This can lead to redness, foreign body sensation, itching, tearing, and pain from the dry areas on the surface of the eye. The eyes may become dry because the tear film evaporates too quickly or because the tears themselves have a chemical imbalance or a combination of both.
People usually begin experiencing dry eye symptoms as they age, but the condition can also result from certain medications, medical conditions, auto-immune diseases, or injuries. Also, any activity that involves concentrating on a task (reading, computer work, sewing and kniting, driving, cross word puzzles) reduces the blink rate and can worsen the condition.
Symptoms of dry eye
- Stinging or burning
- Scratchiness or foreign body sensation
- Discomfort when wearing contact lenses
- Fluctuations in vision
- Eye fatigue
- Tearing (to try to over-compensate for the dry eye)
Dry eye is not only uncomfortable, it can also impair vision and damage the eye’s surface tissues.
Treatment for dry eye
- Lubricating solutions - come in both preservative and non-preservative formulations. They also vary in consistency from watery drops to thicker gels and ointments. They need to be used consistently and frequently to achieve proper results.
- Punctal (tear saver) plugs - are nearly invisible plugs placed in the inner corner of the eyelids. These plugs allow patients to retain more of their own natural tears.
- Eyelid cleaning and massage - a combination of warm compresses, eyelid massage, and gentle cleaning of the eyelids and eyelashes helps increase the oily secretions from the eyelids and improves ocular lubrication.
- Oral medications - various types of medicines (tetracyclines, omega 3 fatty acids) can be used to reduce inflammation and improve the secretion of natural eyelid oils into the tear film
- Restasis – the only FDA approved eye drop that helps improve the chemical composition of the tear film and reduces the inflammatory chemicals that irritate the eye.
- Autologous serum - an advanced technique for severe dry eyes. A small amount of blood is removed from the patient, this is then spun down in a centrifuge, and the remaining serum is used to lubricate the eyes.
- Eyelid surgery - improperly positioned eyelids will result in an inefficient blink. This can contribute to dry eyes, but is readily fixed with eyelid surgery.
Flashes and Floaters
Floaters and flashes are symptoms of the eye that commonly occur as a result of changes to the vitreous gel in the back of the eye. When we are born, the vitreous is firmly attached to the retina and is a thick, firm, jello-like substance. As we age, the vitreous becomes thinner and more watery, and tissue debris and fibers that were once secure in the firm gel can now move around inside the eye, casting shadows on the retina.
Flashes in vision occur as a result of tension from the vitreous gel on the retina in the back of the eye. This causes patients to see brief flashing lights or lightning streaks until the tension resolves. This can take anywhere from several days to a few months to resolve on its own. Floaters occur when fibers move across the vitreous and into your field of vision, causing patients to see specks, strands, webs or other shapes as the fibers cast shadows on the retina. These floaters may be dark or translucent.
These symptoms are most visible when looking at a plain, light background. Flashes and floaters often appear at the same time, although some patients may only experience one symptom.
Patients that develop new floaters or flashes should contact their eye doctor and set up an appointment for a dilated eye exam as soon as possible. Although rare, floaters and flashes are sometimes associated with bleeding inside the eye (vitreous hemorrhage) or retinal detachment.
If you have any further questions regarding these and other eye conditions, please call us today to schedule a consultation.