The etiology of eye irritation (or pseudoirritation) in a child whose eyes are not red (bloodshot) can often be identified by history. The examination in most such children is relatively unremarkable. Most of the disorders associated with this symptom are not dangerous. If the etiology can’t be identified with reasonable certainty, referral to a pediatric ophthalmologist is indicated.

What Shouldn’t Be Missed

Ocular tics are fairly common in childhood, and may present as bilateral frequent forceful blinking. Hemifacial spasm is rare, and is characterized by contraction of the periocular and facial muscles on only half of the face. This may be associated with brainstem or posterior fossa lesions. Imaging is indicated in these patients.

• 1. Idiopathic. Some children are generally more light sensitive than others. They squint in bright light and may want to wear sunglasses or avoid bright situations. These patients tend to have fair skin and light-colored irises.
  
• 2. Blepharitis/dry eyes. Blepharitis is a condition in which the meibomian glands of the eyelids do not function normally. The eyelid margins are usually erythematous and crusts are present (Figure 6–1). This results in an unstable tear film. The tears tend to evaporate rapidly, creating symptoms of eye irritation and frequent blinking. Blepharitis is a common cause of dry eyes, although not all patients with dry eyes have blepharitis. Paradoxically, some patients with dry eyes may have symptoms of excess tearing. This is because there are 2 types of tears: basal tears that keep the eyes moist and comfortable, and reflex tears that are produced in response to irritation. Patients with dry eyes have abnormal basal tears, so they tend to have cyclic symptoms of eye irritation, reflex tears that temporarily improve the symptoms, and then recurrent irritation as the reflex tears evaporate.
  
• 3. Ocular allergy. The key historical feature of ocular allergy is itching. If the child is old enough to reliably articulate this symptom and differentiate it from nonspecific ocular irritation, the diagnosis of allergy is very likely. Many patients with ocular allergies will have other atopic problems, such as reactive airway disease or eczema.
  
• 4. Ocular tics. Tic disorders are frequent during childhood, occurring in approximately 10% of children. Ocular tics present with frequent bilateral forceful blinking, sometimes associated with upward and lateral deviation of the eyes (Figure 6–2A and B). These children do not complain of eye irritation and the eyes are not red. They may, however, be bothered by the symptom, which they cannot control. Most ocular tics are benign and self-limited, but Tourette syndrome should be considered if the child has other associated vocal or motor tics. Ocular tics need to be distinguished from hemifacial spasm. This condition is unilateral, and the eyelid contractions are accompanied by facial and perioral contractions (Figure 6–3). Hemifacial spasm may be caused by central nervous system mass lesions.1
  
• 5. Squint from strabismus. Unilateral squinting in bright light is a common symptom of strabismus, particularly intermittent exotropia. This is not associated with eye pain or redness. Intermittent exotropia is not always easy to elicit on examination.