Refraction is the science that deals with the optical problems of the eye.

Refractive errors

When the eye does not precisely focus the images on the retina then there is a refractive error. The diopter is a measure used to quantify the refractive error and is therefore the extent of the degree to which the light converges or diverges. The eye has a focusing system that is in a relaxed state when we look far away. If we want to focus closely, we must use a muscle inside the eye that remains in contraction for as long as necessary. This is the muscle that weakens around the age of 40, to overcome this it is necessary to use glasses for close reading. In a perfect eye the rays of the images we look at fall exactly on the retina, otherwise you have a clouded vision. Optical defects are usually genetically predetermined and may be present at birth, they are due to an alteration in the length of the eye or cornea or lens.

Emmetropia Normal eye condition

It is the condition of the eye in which there is no refractive error and the images are focused precisely on the retina. In this case the view is normal. The view is clear both in the distance and for near. After 40-45 years of age, reading glasses will be needed.

Farsightedness

It is the most common defect in the world. In contrast to myopia in hyperopic people, the rays fall behind the retina and therefore a convergent lens in the glasses or contact lens is needed. Usually it is already present at birth and can decrease with development. If the degree is low you can do without glasses otherwise you will have discomfort and headache due to an effort by the muscle to focus which must work also for distances.

Ipermetropia: i raggi cadono dietro la retina — Hyperopia the rays fall behind the retina

Myopia

In this case the rays fall in front of the retina and to see clearly it is necessary to place a diverging lens, in front of the eye that perfectly corrects the missing degrees. Myopia usually occurs during the developmental age and stabilises in the twenties. It has a gradual increase. There is often a familiarity.

Miopia: i raggi cadono davanti alla retina — Myopia the rays fall in front of the retina

Astigmatism

This can be present alone or in association with nearsightedness or farsightedness. The defect is due in the vast majority to an ovalization of the cornea and / or less commonly of the crystalline lens. Present at birth and can worsen over time. It is important to exclude in some cases the keratoconus which represents a marked ovalization of the cornea.

Astigmastismo: ovalizzazione della cornea — Astigmatism ovalization of the cornea

Presbyopia

It is the difficulty to see clearly up close that arises around the age of 40, due to a weakening of the focusing muscle. Initially, the use of glasses can also be delayed and this does not cause damage to the eye, but heaviness may be felt around the eyes. If you are nearsighted you can in many cases see well for near by removing your glasses, if instead you were already hyperopic you have even more difficulties and you can have problems even before the age of 40.

Refractive surgery in Rome Eur

About 50{f41b8f6fb753ffddef9325fd3a43d0beafc65648567813d504441f6babbdd7fd} of the population suffers from vision problems correctable with glasses. Refractive surgery offers an alternative to reduce or eliminate total dependence on corrective lenses. Dr. Sciscio can offer you the whole range of refractive surgery. Based on the tests carried out, the best type of approach will be offered in the best interest of safety and the final result.

LASER SURGERY

The excimer laser was developed in 1983 and in 1988 the first clinical studies were headed at St. Thomas Hospital in London by Prof John Marshall, with whom Dr. Sciscio collaborated and started laser surgery in 1999. Corneal laser refractive surgery techniques work by changing the curvature of the cornea. In the short-sighted it is flattened, in the hyperopic the curvature increases and in astigmatism the ovalization is regularised. In addition to these optical defects, nearsightedness-farsightedness-astigmatism, there are others that can only be detected with special equipment that uses wavefront technology. These are the so-called higher order optical aberrations.

LASER SURGERY TECHNIQUES

1) SURFACE TREATMENTS

PRK laser on the surface of the cornea after removing the superficial layer
LASEK laser on the surface of the cornea, the aforementioned stater is finally repositioned
Epi-LASEK before the laser on the surface of the cornea, a tool is used to facilitate the removal of the most superficial part which is subsequently repositioned.

2) INCISIONAL TECHNIQUES
With a mechanical tool, the microkeratome, LASIK first prepares a flap which is lifted to apply the laser and then placed back in place.
IntraLASIK as the previous one but another laser (Femto-laser) is used to prepare the flap.

3) SMILE
SMILE is a new technique that uses only a Femtolaser to create a lenticule within the thickness of the cornea that is then removed. The shape and thickness of the lenticule is designed by the Femtolaser based on the amount of myopia and astigmatism.

NON LASER SURGERY TECHNIQUES

They involve the placement of rings inside the cornea or thin lenses inside the eye. The latter are ones called ICL and are used in cases of high nearsightedness or high farsightedness or when the cornea is thin and it is not possible to proceed with laser. They are similar to contact lenses that are implanted behind the iris, they are completely invisible from the outside and allow a clear vision both near and far.

Refractive surgery in Rome Eur
Dr. Sciscio after evaluating the results of the visit and diagnostics tests will explain the pros and cons of each technique deemed appropriate in your case.