An ophthalmic illumination apparatus, comprising: a condenser ; a light source ; an optical fiber having a core diameter and configured to transmit a light beam output by the light source and focused by the condenser ; the optical fiber including: a proximal portion configured to receive the light beam focused by the condenser onto a focal point at the proximal portion, the proximal portion comprising a first tapered portion comprising a proximal end having a core diameter D, and a terminal end having a core diameter D 2 , wherein Di is greater than D 2 ; a distal portion configured to emit the light beam to illuminate a surgical field; a central portion extending between the proximal portion and the distal portion, wherein the core diameter is constant over the central portion; wherein the proximal portion has a core diameter larger than the core diameters of the central and distal portions; characterized in that at the focal point on the proximal portion of the optical fiber a numerical aperture of the light beam, NA beam , equals a numerical aperture of the optical fiber, NA fiber , divided by N, wherein N equals the core diameter D 1 divided by a core diameter D 2 of the central portion; and wherein the central portion is configured such that the numerical aperture of the light beam, NA beam , is equal to a numerical aperture of the central portion, NA fiber . a condenser ; a light source ; an optical fiber having a core diameter and configured to transmit a light beam output by the light source and focused by the condenser ; the optical fiber including: a proximal portion configured to receive the light beam focused by the condenser onto a focal point at the proximal portion, the proximal portion comprising a first tapered portion comprising a proximal end having a core diameter D, and a terminal end having a core diameter D 2 , wherein Di is greater than D 2 ; a distal portion configured to emit the light beam to illuminate a surgical field; a central portion extending between the proximal portion and the distal portion, wherein the core diameter is constant over the central portion; wherein the proximal portion has a core diameter larger than the core diameters of the central and distal portions; characterized in that at the focal point on the proximal portion of the optical fiber a numerical aperture of the light beam, NA beam , equals a numerical aperture of the optical fiber, NA fiber , divided by N, wherein N equals the core diameter D 1 divided by a core diameter D 2 of the central portion; and wherein the central portion is configured such that the numerical aperture of the light beam, NA beam , is equal to a numerical aperture of the central portion, NA fiber . a proximal portion configured to receive the light beam focused by the condenser onto a focal point at the proximal portion, the proximal portion comprising a first tapered portion comprising a proximal end having a core diameter D, and a terminal end having a core diameter D 2 , wherein Di is greater than D 2 ; a distal portion configured to emit the light beam to illuminate a surgical field; a central portion extending between the proximal portion and the distal portion, wherein the core diameter is constant over the central portion; wherein the proximal portion has a core diameter larger than the core diameters of the central and distal portions; characterized in that at the focal point on the proximal portion of the optical fiber a numerical aperture of the light beam, NA beam , equals a numerical aperture of the optical fiber, NA fiber , divided by N, wherein N equals the core diameter D 1 divided by a core diameter D 2 of the central portion; and wherein the central portion is configured such that the numerical aperture of the light beam, NA beam , is equal to a numerical aperture of the central portion, NA fiber . <EOS>