asti - basa
- astigmatic lens
- astigmatism
- astrocyte
- astrocytic hamartoma
- astrocytoma
- asymmetry
- asymptomatic
- ataxia
- atheroma
- atopic keratoconjunctivitis
- atresia
- atropine
- atropinisation
- autoantibody
- autoantigen
- autoimmune disease
- autoinfarction
- automated perimeter
- autosomal dominant inheritance
- autotherapy
- autotransplant
- avascular zone
- Axenfeld's syndrome
- axial cataract
- axial length of the eye
- axial ray
- background diabetic retinopathy
- bacteria
- bacterial conjunctivitis
- bacteriocidal
- bacteriostatic
- Bagolini's glass
- Bagolini's lens
- Bagolini's test
- band
- band keratopathy
- bandage
- bandage contact lens
- barrier