Prescription glasses for kids: how to choose your child's first pair

Choosing a child's first prescription glasses comes down to three things: a frame sized to the child's face rather than their age, impact-resistant polycarbonate lenses, and a fitting by an optician who regularly works with children. The American Association for Pediatric Ophthalmology and Strabismus (AAPOS) says polycarbonate is the lens children should be given unless the eye doctor decides otherwise, because it resists shattering and blocks ultraviolet light. A good fit means each eye sits in the centre of its lens and the frame touches neither the cheeks nor the lashes. The first weeks vary from child to child: nearsighted children often like their glasses from day one, while farsighted children may need several weeks to get used to them. This guide takes you from the prescription to the end of the first month.

Before the optical shop: understand why your child needs glasses

Children are often prescribed glasses for different reasons than adults, and the reason shapes how the glasses should be worn. The visual system is still developing through the first 12 years of life, so for a child glasses are often part of building vision itself, not just a way to see the board. AAPOS lists four main reasons:

• Clearer vision: the best-known case is nearsightedness, written on the prescription with a minus sign such as -2.00, which blurs the board and anything far away.
• Straightening eyes that turn (strabismus): farsightedness is written with a plus sign such as +3.00, and when it is higher than normal for the child's age it can blur both near and far, and in some children it makes an eye turn inward, which the right glasses help to straighten.
• Strengthening a weak eye (amblyopia, or lazy eye), which can develop when the two eyes have different prescriptions.
• Protecting the better eye when the other eye sees poorly.

Before you leave the clinic, ask the doctor the one question that shapes everything after it: should the glasses be worn all day, or only at school and in front of screens? A child being treated for a lazy eye or crossed eyes usually needs them all day, while a child with mild nearsightedness may need them mainly for distance. Ask too when the next check is due, and keep the paper prescription, or a photo of it, for the optician.

The frame: fit the face, not the age

A child's face is not a shrunken adult face: the bridge of the nose is lower and flatter, the head is still growing, and the glasses will go through play, naps and falls. The right frame is one the child forgets is there; one that slides or pinches ends up in a drawer. Avoid buying a large frame for the child to grow into: it slides down the nose, and the child ends up looking over the lenses instead of through them. Check these points in front of the mirror before you pay:

• Each eye sits in the centre of its lens, both side to side and up and down.
• The frame touches neither the cheeks nor the lashes, even when the child smiles.
• The bridge rests on the nose without sliding: adjustable nose pads on metal frames help with a low bridge, while plastic frames need a bridge designed for children's noses.
• The arms reach the ears without pressing on the sides of the head, and are long enough for the curved end to sit behind the ear rather than on top of it.
• Flexible or spring hinges that bend outward instead of snapping when the child pulls the glasses off with one hand.

Glasses for babies and toddlers usually come with cable temples, arms that curl around the back of the ear. The curled part must not be tight, and the arm must not be too short. Because children outgrow cable frames quickly, AAPOS suggests asking about temple tips: soft ear grips that slip onto the end of an ordinary arm. They work the same way as cables and can be swapped as the child grows. A soft elastic strap is another option for very young or very active children.

Lenses: safety before thinness

For a child, lens material is a safety question first. Polycarbonate resists shattering, so a ball or a fall is far less likely to send fragments into the eye; it is also light on a small nose, works well with strong prescriptions, blocks ultraviolet light on its own, and usually comes with a scratch-resistant coating. Trivex is a similar impact-resistant option some opticians offer; check with the eye doctor before choosing it over polycarbonate. Glass lenses have no place in a child's glasses. Beyond the material, a few extras are worth weighing:

• Anti-reflective coating: optional; it cuts reflections from classroom lights and screens, but shows smudges more and needs gentler cleaning.
• Light-reactive (photochromic) lenses: convenient for a child moving between classroom and playground, but they darken little inside a car and do not replace proper sunglasses for long hours in the sun.
• Bifocals: some children need them, such as those with certain types of crossed eyes or who have had cataract surgery, with a stronger reading section at the bottom of the lens. In children the dividing line sits higher than in adults, through the middle of the pupil or just below it, and the line should be easy to see so the child knows where to look through the reading section.

Where you buy matters as much as what you buy. According to AAPOS, optical shops that work with children a lot tend to fit their glasses better and carry a wider choice of children's frames. Ask about the warranty and exactly what it covers: most warranties do not cover lost glasses, but some may cover breakage or scratched lenses.

The first weeks: patience with a plan

Do not judge the glasses on day one. AAPOS notes that nearsighted children often like their glasses straight away, while children with farsightedness or astigmatism may take several weeks to get used to them. A nearsighted child sees the board turn sharp at once, while a farsighted child's eyes may need time to let go of a focusing effort they have grown used to. A positive tone at home matters more than any reward.

• Put the glasses on first thing in the morning as part of getting dressed, and follow the doctor's instructions on full-time or part-time wear.
• Tell the teacher, so the child sits where they can see the board and someone notices if the glasses come off.
• Let the child choose the colour or shape from the frames that fit, so the glasses become something of their own.
• Teach the simple rule AAPOS uses: glasses stay on your face or go in their case.
• If the child keeps pulling them off after a few weeks, go back to the eye doctor: the prescription may need rechecking, or the doctor may prescribe drops to help the eyes adjust. Have the optician check the fit as well, since pinching or sliding is a common reason that can be fixed. Do not wait weeks, though, if the child complains of double vision or an eye turn appears or gets worse: contact the eye doctor promptly.

The worry that glasses will weaken the eyes or make a child dependent on them has no basis: AAPOS states that wearing glasses will not worsen a child's eyesight or make them more dependent on glasses, and that, in some cases, skipping prescribed glasses can disrupt normal vision development and lead to permanent vision loss (amblyopia). For a child whose glasses treat an inward eye turn, AAPOS adds that the eyes may still cross with the glasses off, and the crossing can even seem worse at first; what counts is that the eyes are straight with the glasses on.

Care, a spare pair, and knowing when the glasses have been outgrown

Children's glasses live a hard life, and a few habits can add months to their life. Put them in their case whenever the child takes them off, never set them down lens-first, clean them with a soft cotton cloth or a lens cloth, and do not try to bend a frame back into shape yourself: a bent frame goes to the optician, who can adjust it without breaking it. A second pair, even in a simpler frame, saves days of blurry vision when the first one breaks, and for a child who wears glasses all day it is close to essential. For football and other ball sports, everyday glasses are not eye protection: ask about protective sports goggles made with the child's prescription.

Watch for the signs that the frame has become too small or the prescription has changed:

• The arm ends before the bend of the ear, or the frame looks narrower than the child's face.
• Red marks on the nose or behind the ears, or constant sliding even after adjustment.
• Squinting, sitting closer to the screen, or complaining that the board is hard to see, even with the glasses on.

The absence of these signs does not mean the prescription is stable: it can change without any of them, so keep to the follow-up schedule the doctor sets.