Glossary
E - H
Glossary of terms E - H
Ectasia
A progressive corneal thinning and bulging.
Emmetropes
People who have no refractive error.
Emmetropia
The ophthalmic term for normal sight without glasses: no near-sightedness, far-sightedness or astigmatism. This is what laser surgery aims to achieve.
Endophthalmitis
An inflammation within the eye. Endophthamistis usually is used to indicate an infectious disease as occasionally occurs as a complication of ICL surgery. It should be treated with utmost urgency to avoid the loss of the eye.
Endothelium
The inner layer of cells on the inside surface of the cornea.
Erosion
Corneal erosion is where cells are not being replaced and the blinking action can cause the eye to be painful and sore, particularly on waking.
Epithelium
Transparent layer of protective watery loose cells covering the eye constantly by renewing ‘skin'.
Exophoria
This is a muscle imbalance, which makes your eyes turn outwards.
Eye-pressure Test
A standard eye test that determines the fluid pressure inside the eye. The test is called a tonometry. Increased pressure within the eye is a possible sign of glaucoma and must be treated to avoid blindness.
Eye Test
An eye examination used to measure the power of glasses needed. The level of correction for best possible sight, also known as "refraction" (or R).
Far-Sightedness
The American term for long sight (hyperopia).
Fixation
The ability to direct and maintain steady visual attention on a target.
FRCOphth
Fellow of the Royal College of Ophthalmologists.
FRCS
Fellow of the Royal College of Surgeons.
Exocin drops
Antibiotics sometimes favoured by doctors for use after treatment.
Eye drops
Drugs administered to the eye in drop form:
Tropicomide - Dilating drops to examine the back of the eye.
Amethecain - Anaesthetic drops to numb eyes before treatment. Proxymetacain - Anaesthetic drops to numb eyes before treatment. Hypromellose - Administered for dry eyes.
Pilocarpine - Constricting drops for the pupil.
FML - Steroid drops administered to slow down the healing process. Mainly used for patients who are regressing. Exocin- See above.
Eye patch
A gauze pad which is placed on your eye with micropore tape to keep your eyelids closed. This is to be removed on the treating doctor's instruction, usually within 24 hours.
Femtosecond Laser
An infrared range laser that delivers pulses of energy within the cornea, causing a small controlled explosion of gas that separates the layers of the cornea. The femtosecond laser for ophthalmology is used to create a LASIK flap in a procedure commonly called IntraLASIK or 'all laser LASIK'.
Flap
In LASIK a thin layer is cut into the cornea to create the ‘flap'. The hinge should be sufficient to replace the flap properly after treatment. Complications can occur such as the ‘free flap' where the flap becomes detached, or an incomplete flap or buttonhole flap etc.
Flap hinge
The point at which the flap, cut by the microkeratome, remains connected to the cornea. This hinge may be nasal (toward the nose) or superior (toward the top).
Flap - incomplete
If there has been a malfunction of the microkeratome, the flap creation process may have been aborted prematurely, resulting in an incomplete flap. In this instance the laser treatment is abandoned and the flap is replaced and left for three months to heal before laser treatment can be given again.
Floaters
Congealment of the liquid inside the eye into lumps which float around in the eye causing blurring if they pass through the visual axis. Floaters are not necessarily a contra-indication to treatment but they cannot be cured by Epi-LASEK or LASIK.
Fluoroscein staining
A way to test for dryness on the ocular surface. A tiny amount of sodium fluorescein dye is place in the tear film. The colour will make microscopic dots appear where the eye has become dry. Excessive staining is an indication of dryness which may need further treatment.
Flurometholene
Steroid eye drops used for local treatment of inflammation.
FML drops
Fluorometholone (with liquifilm) -mild steroid drops- 5ml bottles prescribed for short-term use only. Used in local treatment for inflammation. Reduced tendency to raise IOP. Only prescribed at the doctor's discretion and is obtained from the local chemist, chargeable to the patient. Steriods have a tendency to raise internal eye pressure and the eyes must be monitored closely to avoid glaucoma, which in prolonged cases can cause blindness.
Focimeter
A machine to measure the strength of glasses. Can be used to get a measurement of your prescription from a pair of glasses in place of a printed prescription.
Focus
Point at which light rays meet. When these rays focus correctly on the retina (at the back of the eye) the image is clear. In short sighted people the light rays meet just too short of the retina and images are blurred. In long-sighted people the light rays meet just behind the retina so near vision is not in focus.
Forme Fruste Keratoconus
This is keratoconus in the very early stages and is a contra-indication to laser treatment.
Free Cap (Flap)
A complication occurring during the creation of the LASIK flap, where there is no hinge and the flap becomes free-standing. Usually, laser treatment can proceed and the flap is replaced normally.
Fuch's Corneal Distrophy
A contra-indication.
Fucithalmic
Eye drops used for bacterial infections
Funduscopy
Examination of the back of the eye (fundus) to ensure that it is healthy and not showing any signs of detachment, retinal holes or tears. Sometimes it is necessary to put dilating drops (Tropicomide) into the eye to examine the retina more closely- particularly for people who are over -6.00 dioptres. In this case it is not possible for the patient to drive home as they should wait until the pupil has retracted to its normal size.
Gas permeable
Type of contact lens allowing oxygen to penetrate through, enabling the cornea to breathe. Gas permeable lenses need to be removed about three weeks prior to the consultation and treatment.
Gentamicin
Eye drops used for bacterial infections.
Ghost image
A fainter second image of the object you are viewing.
Glare
Flaring and star burst effect when looking at bright lights, particularly noticeable at night. Can be a symptom of halos and haze and is the most common side effect of laser treatment. See Freevision.com for simulations.
Glaucoma
Increased pressure of the fluid in the eye, which and can cause irreversible loss of sight. Usually occurs in middle age and there is frequently a family history of glaucoma. Not an ideal candidate for laser treatment, if the pressure is not under control.
Globe
The eyeball
Gritty eye
After the first 12-24 hours, following Epi-LASEK the eye may start to feel gritty or sting. This will gradually improve over the next two to four days. Patients must try not to rub the eye and should rest it as much as possible.
Guanethidine
Drops normally used to lower the internal eye pressure for patients with glaucoma.
Guarantee
Doctor's ethical guidelines do not allow for 'guarantees'. Epi-LASEK and LASIK are medical procedures and like all medical procedures, cannot be guaranteed.
Halos
This side effect is associated with patients who have large pupils. Our lasers can treat 6.5mm pupils but this can be expanded to a treatment zone of 9mm. If the pupil dilates beyond the treated area then the patient may experience this halo effect at night. Glare around bright lights can be particularly distracting when driving.
Hansatome
The flap cutting device is the microkeratome. It is used for creating the corneal flap during to LASIK treatment.
Hard lens
Hard or rigid lenses can correct small amounts of astigmatism because the tear film fills the gap between the lens and the uneven spots on the cornea. Soft lenses cannot do this because they hug to the surface of the eye. Hard lenses need to be removed and not worn for three weeks prior to laser treatment.
Haze
Also referred to as healing tissue or scar tissue. This can affect Epi-LASEK patients to varying degrees but it is usually mild and clears up within a few months. Patients sometimes complain of glare at night and vision that is similar to that when looking through frosted glass or dirty glasses. Limiting Epi-LASEK to -5d has reduced incidence of haze to minimal levels.
Hereditary
Conditions passed down from generation to generation. It is important to advise the treating doctor of any known medical conditions in the patient's parents e.g. glaucoma, as some eye conditions are hereditary. The doctor can then consider these specific symptoms.
Herpes Simplex Keratitis
A virus infection of the cornea which would endanger the cornea if treated by Epi-LASEK or LASIK. Contra-indication.
Higher Order Aberrations
Optical (corneal) irregularities not measurable with conventional eye exams and not correctable with spectacles of soft contact lenses. Technically higher order aberrations referred to in Laser vision correction are ocular aberrations detected by Wavefront diagnosis.
Homatropine
Drops used to dilate pupils
Hypromellose
Artificial tears. To be used if your eyes are not producing enough natural tears and causing you discomfort. They are available over the counter without prescription. If discomfort continues when using these drops, or it is severe, the patient should contact us for an appointment.
Hyperopes
People who are farsighted
Hyperopia
The ophthalmic term for farsightedness. In the hyperopic eye, images are focused in back of the retina. The hyperopic eye is often described as being too flat or too short.
