A vitamin D compound according to the following formula wherein R is or wherein R 1 and R 2 are H, methyl or 3'-hydroxypropylidine, or taken together as =CH 2 or methylene; wherein R 3 and R 4 are selected from H, alkyl (1-3 carbons), alkoxy, and can be the same or different from each other; wherein X is a hydroxyl or protected hydroxyl group; wherein A is oxygen or carbon, with the proviso that if A is oxygen, then R 4 is absent; and wherein C and D are H or taken together as =CH 2; for use in (i) a method of reducing ocular hypertension in a subject, the method comprising administering the vitamin D compound to at least one eye, wherein the intraocular pressure of the subject is reduced by at least 15%; (ii) a method of preventing development of glaucoma in a subject at risk of developing glaucoma, wherein the intraocular pressure of the subject is reduced by at least 15%; (iii) a method of reducing intraocular pressure in a subject's eyes, the method comprising the steps of: a) determining a baseline intraocular pressure of a first eye; b1) determining a baseline intraocular pressure of a second eye; b2) administering to the first and second eye a therapeutically effective amount of the vitamin D compound; c) measuring the intraocular pressure of the first and second eye; wherein the ocular hypertension in the first and second eye is reduced by at least 15%; or (iv) a method of reducing intraocular pressure in a subject's eyes, the method comprising the steps of: a) determining a baseline intraocular pressure of a first eye; b1) determining a baseline intraocular pressure of a second eye; b2) administering to the first eye a therapeutically effective amount of the vitamin D compound; c) measuring the intraocular pressure of the first and second eye; wherein the ocular hypertension in the first and second eye is reduced by at least 15%. wherein R 1 and R 2 are H, methyl or 3'-hydroxypropylidine, or taken together as =CH 2 or methylene; wherein R 3 and R 4 are selected from H, alkyl (1-3 carbons), alkoxy, and can be the same or different from each other; wherein X is a hydroxyl or protected hydroxyl group; wherein A is oxygen or carbon, with the proviso that if A is oxygen, then R 4 is absent; and wherein C and D are H or taken together as =CH 2; (i) a method of reducing ocular hypertension in a subject, the method comprising administering the vitamin D compound to at least one eye, wherein the intraocular pressure of the subject is reduced by at least 15%; (ii) a method of preventing development of glaucoma in a subject at risk of developing glaucoma, wherein the intraocular pressure of the subject is reduced by at least 15%; (iii) a method of reducing intraocular pressure in a subject's eyes, the method comprising the steps of: a) determining a baseline intraocular pressure of a first eye; b1) determining a baseline intraocular pressure of a second eye; b2) administering to the first and second eye a therapeutically effective amount of the vitamin D compound; c) measuring the intraocular pressure of the first and second eye; wherein the ocular hypertension in the first and second eye is reduced by at least 15%; or a) determining a baseline intraocular pressure of a first eye; b1) determining a baseline intraocular pressure of a second eye; b2) administering to the first and second eye a therapeutically effective amount of the vitamin D compound; c) measuring the intraocular pressure of the first and second eye; wherein the ocular hypertension in the first and second eye is reduced by at least 15%; or (iv) a method of reducing intraocular pressure in a subject's eyes, the method comprising the steps of: a) determining a baseline intraocular pressure of a first eye; b1) determining a baseline intraocular pressure of a second eye; b2) administering to the first eye a therapeutically effective amount of the vitamin D compound; c) measuring the intraocular pressure of the first and second eye; wherein the ocular hypertension in the first and second eye is reduced by at least 15%. a) determining a baseline intraocular pressure of a first eye; b1) determining a baseline intraocular pressure of a second eye; b2) administering to the first eye a therapeutically effective amount of the vitamin D compound; c) measuring the intraocular pressure of the first and second eye; wherein the ocular hypertension in the first and second eye is reduced by at least 15%.