| hard sore | The primary skin lesion of syphilis which begins at the site of infection after an interval of 10-30 days as a papule or red ulcerated skin lesion. (27 Sep 1997) |
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| hard tarter | <dentistry> A calcium salt concretion which forms on your teeth. Calculus deposits form on the teeth in areas which you do not floss or brush. If these concretions are left to build up on the tooth enamel, they will irritate the gum tissue, push it away from the tooth and promote progressive bone loss. Eventually the teeth can loosen and fall out. These deposits can be removed by a dentist or a dental hygienist on an annual to biannual basis. (27 Sep 1997) |
| hard tissue | Tissue that has become mineralised, tissue having a firm intercellular substance, e.g., cartilage and bone. (05 Mar 2000) |
| hard tubercle | A tubercle lacking necrosis. (05 Mar 2000) |
| hard ulcer | <dermatology> The primary skin lesion of syphilis which begins at the site of infection after an interval of 10-30 days as a papule or red ulcerated skin lesion. (27 Sep 1997) |
| hard water | <chemistry> Hard water is water which contains minerals like calcium carbonate, magnesium carbonate, bicarbonates, sulphates, or chlorides, because it has been exposed to rocks or rocky soils. Hard water can corrode, discolour, or deposit its minerals, in and around materials such as water pipes. (09 Oct 1997) |
| annular cataract | Congenital cataract in which a central white membrane replaces the nucleus. Synonym: disk-shaped cataract, life-belt cataract, umbilicated cataract. (05 Mar 2000) |
| arborescent cataract | An obsolete term for dendritic cataract. (05 Mar 2000) |
| atopic cataract | A cataract associated with atopic dermatitis. (05 Mar 2000) |
| axial cataract | A lenticular opacity in the visual axis of the lens. (05 Mar 2000) |
| black cataract | A cataract in which the lens is hardened and of a dark brown colour. In the 19th century, German black cataract meant gutta severa (q.v.). Synonym: cataracta brunescens, cataracta nigra. (05 Mar 2000) |
| blue cataract | Coronary cataract of bluish colour. Synonym: cataracta cerulea. (05 Mar 2000) |
| capsular cataract | A cataract in which the opacity affects the capsule only. (05 Mar 2000) |
| capsulolenticular cataract | A cataract in which both the lens and its capsule are involved. See: membranous cataract. (05 Mar 2000) |
| galactose cataract | A neonatal cataract associated with intralenticular accumulation of galactose alcohol. See: galactosaemia. (05 Mar 2000) |