Jyotirmay Eye Clinic

Dispensing of the spectacles in children is Different than in adults.

Children have different facial and nasal structure hence the frames are different.
Children have higher safety requirements hence the durability of frames and safety features of lenses are different.
Children have different visual requirements hence their spectacle prescription guidelines are different.

When selecting frames for children, safety should be the first concern followed by the fitting requirement and then the looks.
Frame should be able to hold the spectacle lenses in the required position well.
Frame with correct vertical height should be chosen so as to cover the eye and peripheral orbit of the child completely.
The material should be corrosion free.
Of-course, it should have better acceptance by the child than the good cosmetic appearance as decided by the parents.
Well fitted lens (larger lens size than the eye wire) to prevent popping out of lens from spectacle
Flexible temples.

For children < 3-4 years of age, MiraflexTM is the best, however, inform the optician to fit the lenses properly as they sometimes fall off.
Half rimless / total rimless frames are best avoided in children – lens falling off / chipping is common.
Plastic frames are better than metal frames in terms of retaining good fitting for long.
Silicon nose rests/pads are useful to reduce pressure imprints on the nose.
Round/oval eye wire is better than the rectangular ones as it covers the eye
Middle level bridge provide better coverage while looking up as well as down than a high/top level bridge
A temple with side-springs is useful as it provides excellent fit for very long.

Avoid glass material as they have a low safety profile.
CR39 plastic is cheaper compared to Polycarbonate material. However, polycarbonate is tougher.
Anti scratch coating is highly recommended for all plastic lenses.
Anti reflective coating and/or high index lenses are necessary for >4diopter lenses only.
Bifocal lenses in children must have a large lower segment exactly as shown in the picture. They are expensive, more difficult to make and may need different/special frames so that there is a large upper as well as lower segment.
Opticians often make mistakes in making bifocals in children. They apply their experience regarding adults in making those glasses for children. Make sure you have informed them not to do so.

Less than 4 years old need flexible frames since the nasal bridge is not developed.
Middle level bridge is better – gives good upper and lower field coverage.
Comfortable frames not restricting children’s daily activities.
Rimless or half rimlees frames are best avoided.

Bridge should be such that it fits on the child's nose comfortably. Bridge should not be too wide or too narrow allowing the child to peep from above the frame.

For children less than 4 years, Soft malleable plastic, flexible with adjustable elastic band are advisable.
Plastic frames are advisable for children, to prevent possible injury from metal frames and also to prevent Corrosion.
Plastic frames are also more durable.

Temple of any frame selected should follow the mastoid region smoothly, so that it holds the frame front in position. Temples should not be too tight or loose, since it may get uncomfortable for children. Same holds true for Adults as well.

For children it should be Fibre lens (Also known as Colombia resin 39 / CR-39)
Polycarbonate lenses can also be used. They are more expensive and tougher, hence advised in patients who are one eyed.
Strictly NO to glass lenses.

Anti reflective coating and /or High index lenses are necessary for greater than 4 dioptre lenses only.
Bifocal lenses (Executive bifocal) in children should have a larger lower segment. They are expensive, more difficult to make and may need different/special frames so that there is a large upper as well as lower segment.
Progressive lenses when prescribed in children should be selected carefully due to a wide range of designs. Progressive lenses in children should have a wide corridor to accommodate correction of long distances, intermediate and reading activities comfortably.
Centration plays a very important role in progressive lenses.
Photogray lenses are advisable for children sensitive to light or who are on atropine drops to prevent myopia progression.

Although most of the fibre lenses come with scratch resistant coating, they cannot be completely scratch proof.
Position and amount of scratches, lens pit or chipped off lenses matters since they can result in blurred vision if present at the center of lens. Such lenses should be changed.
To avoid scratching of lenses, it should be wiped with Soft cloth (microfiber) provided by the optician.
When spectacle is not being used, it should be kept in a frame case, with the lens facing upward.
Oily marks, Finger smudges can be cleansed easily with the solution available at opticians.

Four point touch test	All four points on the spectacle frame (two points from each side of eye wire and one each from temple) should touch the flat surface simultaneously when placed as shown in Figure 1b
Eye wire	Should cover both the eyes completely all around permitting the patient to view from the spectacle in various ocular positions and head positions without coming in contact of periocular skin
Nose pads	They should sit symmetrically on the lateral side of the nose bridge and it should be angled in a manner that prevent repeated slippage or excessively close placement of spectacle lens resulting in eyelash brushing the lens or repeated oil/sweat drop-lets from eye brow fogging/smudging the lens

Parallelism	The temples should be parallel to each other
Pressure	There should be mild, uniform and symmetric pressure of the temples on the forehead without causing serious imprinting on the skin. A metallic component of the temple should not come in contact of skin
Length	The temple should not project more than 2 mm out beyond the mastoid bone

Centration error in millimeters (mm)	The optical center should be within 2 mm of visual axis
Power error in D	≤0.25D
Axis error in degrees	≤5°
Surface quality	The surface should have to fractures/pitting/scratches in the center of the lens