Posted on December 22, 2017
Farsightedness, called hyperopia by your doctor, is a condition in which distance vision is clear, but vision for near objects is blurred. This happens when the eyeball. is shorter than average or when the cornea is too flat. Because of this, the rays of light entering the eye are focused behind the retina instead of on it. This makes your near vision blurred, sometimes along with distance vision also.
Farsightedness, like nearsightedness, may be accompanied by astigmatism which causes an overall visual blurry. This is caused by an uneven curvature of the cornea, with flattening or steepening in different axes. This disrupts focus for both near and distant vision.
Understanding Differences between Presbyopia and Farsightedness
A similar vision problem, called presbyopia, also results presents as blurring of vision for near, with no problems in focusing at distant objects. Presbyopia is a disease of middle age, often presenting in the fourth decade of life, and worsens with age. In presbyopia, the natural lens of the eye becomes less elastic over time, making it difficult to focus on near objects. The symptoms of presbyopia are similar to hyperopia, but the possible treatment options are different.
Treatment for Farsightedness
Your doctor prescribes convex lenses to remedy this situation, that is, lenses with a positive dioptric power to focus the light on to the retina again. These lenses can be fitted into either your spectacles, or contact lenses. In case you do not want to be dependent on contact lenses or glasses for better vision, your doctor will perform a comprehensive eye exam, and suggest fo you the refractive surgery best suited to your case. In the majority of people with nearsightedness, this surgery is LASIK in one of its forms.
LASIK surgery is the most common refractive surgery used to correct farsightedness because of its safety and efficacy. Even though LASIK cannot increase the length of the eyeball, it reshapes the corneal curvature by making it more steep, to ensure that the light entering the eye is focused correctly on the retina. It must be kept in mind that most cases of farsightedness can be adequately corrected through LASIK. LASIK, however, will not cure the accompanying presbyopia in patients more than forty years of age, and this subgroup of patients will still need reading glasses for near work.
What happens during LASIK?
During LASIK, a small corneal is made by your doctor using either a manual keratome (in common parlance, a mechanised knife), or by laser as in blade free LASIK surgery. After this, he or she will modify the curvature of the cornea by ablating apart of the tissue. This is the procedure that uses the actual laser in all versions of LASIK. This steepening of the cornea is carried out by the laser which is controlled by a sophisticated computer, which ensures that the resulting shape of the cornea is such that all rays of light entering the eye are focused directly on the retina, ensuring perfect vision.
There are several modifications of LASIK available for laser vision correction, including techniques in which a very thin flap is raised or no flap is raised, or the flap is raised using a laser. Given that each of these comes with distinct of advantages and disadvantages, your doctor will suggest the option best suited to your eyes.
Are you eligible for LASIK?
To determine your eligibility for laser vision correction, your doctor will need to evaluate your eyes comprehensively. The tests that must be done include measurements of the refractive power of the eye, and a detailed dilated evaluation of the retina, as well a measurement of your corneal curvature and it’s thickness.
Your doctor will also want to make sure that your power of glasses has been constant for at least a year, before recommending the procedure, so it is a good idea to carry your old glasses and prescriptions when you go for the check-up. Patients less than eighteen years old are not eligible for LASIK, as the refractive power of the eyes continues to change during the growing years. .
Also, LASIK is best suited for mild to moderate farsightedness, and in case you wear a high plus number for vision correction, your doctor will discuss with you the various options available.
Patients with the following disorders of the eye, are not suitable for LASIK:
- Keratoconus: or conical cornea, a disease which results in corneal thinning and protrusion.
- Keratitis: or corneal infection.
- Uveitis, which is an inflammation of the iris, the inner coat of the eye.
- Eye injuries or lid disorders.
- Severe dry eyes.
- Large pupils, especially if large in dim light.
- Glaucoma, a disease of the eye in which the eye pressures go up and damange the nerve of the eye.
Issues of general health which may impact the visual results after LASIK include the following, and your doctor will want to rule them out before advising the surgery:
- Pregnancy and breast-feeding, since they may cause temporary fluctuations in the refractive power of the eye. It is better to wait until around six months after stopping breast feeding before any refractive surgery.
- Any autoimmune diseases and connective tissue disorders like rheumatoid arthritis, lupus, SLE etc.
- Immuno-suppressed states due to medication, or HIV/ AIDS.
- Uncontrolled Diabetes Mellitus.