Faq

When you take a picture, the lens in the front of the camera allows light through and focuses that light on the film that covers the back inside wall of the camera. When the light hits the film, a picture is taken. The eye works in much the same way. The front parts of the eye (the cornea, pupil and lens) are clear and allow light to pass through. The light also passes through the large space in the center of the eye called the vitreous cavity. The vitreous cavity is filled with a clear, jelly-like substance called the vitreous or vitreous gel. The light is focused by the cornea and the lens onto a thin layer of tissue called the retina, which covers the back inside wall of the eye. The retina is like the film in a camera. It is the seeing tissue of the eye. When the focused light hits the retina, a picture is taken. Messages about this picture are sent to the brain through the optic nerve. This is how we see.

Most physicians test vision as part of a childs medical examination. They may refer a child to an ophthalmologist (a medical eye doctor) if there is any sign of an eye condition. The American Academy of Ophthalmology and the American Academy of Pediatrics recommend the first vision screening occur in the hospital as part of a newborn baby’s discharge examination.

Visual function (including ocular alignment, etc.) also should be checked by the pediatrician or family physician during routine well-child exams (typically at two, four and six months of age). Later amblyopia and alignment screenings should take place at three years of age and then yearly after school age.
If you suspect your child suffers from decreased vision – amblyopia (poor vision in an otherwise normal appearing eye), refractive error (nearsightedness or farsightedness) or strabismus (misalignment of the eye in any direction) – or if there are hereditary factors that might predispose your child to eye disease, please make an appointment with an ophthalmologist as soon as possible. New techniques make it possible to test vision in infants and young children. If there is a family history of misaligned eyes, childhood cataracts or a serious eye disease, an ophthalmologist can begin checking your child’s vision at a very early age.

Adult examinations of the eyes should be performed on a regular basis. Young adults (ages 20 – 39) should have their eyes examined every three-five year.

Adults ages (ages 40 – 64) should have their eyes examined every two-four year.

Seniors (over 65 years of age) should have their eyes examined every one-two year.

High risk adults include:

• People with diabetes
• People with glaucoma or strong family history of glaucoma
• People with AIDS/HIV

Acuity is the measure of the eyes ability to distinguish the smallest identifiable letter or symbol, its details and shape, usually at a distance of 20 feet. This measurement is usually given in a fraction. The top number refers to the testing distance measured in feet and the bottom number is the distance from which a normal eye should see the letter or shape. So, perfect vision is 20/20. If your vision is 20/60, that means what you can see at a distance of 20 feet, someone with perfect vision can see at a distance of 60 feet.

6 meters is nearly equal to 20 feets. Thus, the denominations are used accordingly.

Myopia, Hyperopia and Astigmatism are commonly referred to refractive errors.

Myopia is often referred to as “short-sightedness” or “near-sighted”. An eye is myopic when the “far point”; a point at which light from an object is focussed on the retina, is located at a finite distance in front of the eye. Myopia can be due to either an eye which is too long relative to the optical power of the eye (axial myopia), or because the optical power of the eye is too high relative to the length of the standard eye (refractive myopia). The focus is correctly adjusted with a “minus” power lens, or concave lens.

Hyperopia is often referred to as “long-sightedness” or “far-sighted”. An eye is hyperopic when the far point is at a virtual point behind the eye. Generally the hyperopic eye is too short with respect to the refractive state of the standard eye (ie an emmetropic eye or eye requiring no optical correction) or because the optical power of the eye is too low relative to the length of the standard eye. The focus is correctly adjusted using a “plus” lens power or convex lens.

Emmetropia is just another name for an eye that has no optical defects and a precise image is formed on the retina.

An astigmatic eye generally has two different meridians, at 90degrees to each other, which cause images to focus in different planes for each meridian. The meridians can each be either myopic, hyperopic or emmetropic. The correction for astigmatism is a lens power at a particular direction of orientation [ see section 4.1 ] Astigmatism causes images to be out of focus no matter what the distance. It is possible for an astigmatic eye to minimise the blur by accommodating, or focusing to bring the “circle of least confusion” onto the retina.

Presbyopia is the physiological insufficiency of accommodation where the person feels difficulty to focus the objects at near. This generally occurs at around the age of 40.

The selection of ophthalmic lens is entirely based of visual demands and the choice of the patient. The role of the technicians in the refraction room or the optometrist is to guide the patient in selection of the lens based on the age, lens materials, refractive errors and the availability of the various coatings in the lens with its potential features and advantages.

Globally, the prescription generated date usually expires in a year. However, if there is significant change in the powers of the eye in certain circumstances, there may be need of the prescription.

Globally, the prescription generated date usually expires in a year. However, if there is significant change in the powers of the eye in certain circumstances, there may be need of the prescription.

Soft lenses are manufactured from a plastic hydrogel polymer, HydroxyEthylMethacrylate (HEMA) which has a varying water content (38% – ~70%). Lens size is between 13.00 and 14.50mm. Centre thickness from ~30um.

Hard contact lenses are manufactured from a rigid material, PolyMethylMethacrylate (PMMA). This material can be combined with other plastics to increase the oxygen permeability. Lens size is between 8.0mm and 10.00mm. Centre thickness from ~100um

Yes, the child can wear contact lens which increases visual performances and is safer too when compared to spectacles.

No, there is high incidence of inflammatory changes when used homemade solution. Its always safer to use prescribed contact lens cleaning agents and solutions.

It’s not that dry eye are contra-indicated for the use of contact lens. There are certain contact lens which are recommended for those having dry eyes.

The contact lens adheres onto the corneal or corneo-scleral zone. And, a well-fitted lens moves along with the eye movement, thus, the contact lens cannot get lost within the eye as there are no other exit points. Thus, it is recommended that the contact lens users must the proper insertion and removal techniques from the contact lenes specialist.

Benefits: – no need to wear glasses – no spectacle scotoma – that is “blind-spot” due to frame edge – overcome problems of spectacle magnification, especially when large difference in spectacle prescription between the two eyes.

Risks: – corneal odema – corneal ulcers – contact lens induced conjunctivitis Permanent Solution : Lasik treatment to get rid of contact lens / spectacles.

Keratoconus (conical cornea) is an recessive inherited condition usually apparent between the ages of 10-25yrs. Incidence of the condition is approximately 1 in 5,000. The condition manifests as a thinning of the corneal apex, or central area of the cornea. With the weakening of the tissue there is a bulging of the tissue which increases the myopia of the affected eye. Initial correction is via spectacles whereby reasonable vision can be attained. Subsequent treatment is via a rigid contact lens which will provide a new front surface to the optical system of the eye.

Similarly, Keratoglobus is a rare non-inflammatory corneal thinning disorder characterized by generalized thinning and globular ectasis (protrusion) of the cornea. The non-inflammatory corneal ectasias are a group of disorders characterized by corneal thinning, protrusion, and scarring.

Yes, viral conjunctivitis (pink-eye) is very common and is extremely contagious. Avoid touching eyes with your hands, wash hands frequently, do not share towels, and avoid work, school or daycare activities for a least five days or as long as discharge is present.

No, the eye drops must be used as per the advices of the eye care professionals. However, there are some over-the-counters drugs (OTCs), but without a proper eye check-up it is unsafe to use the eye drops even if the same problem arises.

Your eye surgeon advises for the cataract surgery to restore the eye sight. It is recommended to visit the counsellor or counselling department in the eye hospital for the choice of the surgical modality, choice of intra-ocular lens (IOLs) and pre and post operative guidelines.

Glaucoma is one of the sight-threatening disease of the optic nerve which may be acute or chronic. Thus, to diagnose glaucoma, your eye doctor advises a suspicious case of glaucoma to undergo a series of tests like visual field testing, optical coherence tomography of the optic nerve head, corneal thickness measurement, intra ocular pressure (IOP) measurement, etc

Lazy eye (amblyopia) is reduced vision in one eye caused by abnormal visual development early in life. The weaker — or lazy — eye often wanders inward or outward. Amblyopia generally develops from birth up to age 7 years. It is the leading cause of decreased vision among children. There are newer treatment methods like computer assisted vision therapies helping to better function the weaker eye.

Low vision is a term describing a level of vision below normal (20/70 or worse) that cannot be corrected with conventional glasses. Low vision is not the same as blindness. People with low vision can use their sight. However, low vision may interfere with the performance of daily activities, such as reading or driving.

If neither of your eyes can see better than 20/60 without improvement from glasses or contacts, you may be defined as visually impaired. In addition, poor night vision, limited side vision, double vision and loss of vision in one eye may also determine visual impairment.

No. Currently, there is no way to transplant a whole eye. However, corneas have been successfully transplanted for many years.

Ocular prosthesis is an artificial eye, which is implanted in patients who have lost their eye due to various causes such as trauma, surgery, cancer, or in patients with shrunken damaged eyes (phthisical eyes), congenital absence (anophthalmos) or abnormally small sized eyes (microphthalmos) with nil visual potential.