
	Where results make sense

Topic: Base curve radius

Related Topics

Contact lens

Intraocular lens

Dioptre

Ciliary muscle

Astigmatism

Diameter

Management

	Contact Lens Spectrum
		The second curve is the reverse or return zone which is approximately 0.6mm wide and steeper than the base curve radius by two to 2.6 times the amount the base curve is flatter than K, and can range from 6.00D to 12.00D steeper than the base curve radius.
		The outer curve of the lens is the peripheral curve, which is very similar to the peripheral curve of the three-zone design; it is most commonly 0.4mm wide with a radius of curvature of 10.50mm to 12.50mm.
		Base curve radius determination is accomplished by fitting the lens flatter than K by the amount of desired refractive change +0.75D.
	www.clspectrum.com /article.aspx?article=12046 (3525 words)

	Review of Ophthalmology
		The primary curve on the posterior surface of a RGP lens is the base curve.
		The ideal base curve relationship on a cornea with with-the-rule corneal astigmatism exhibits alignment or slight apical clearance across the central cornea and along the flatter horizontal meridian.
		The sole function of the flatter peripheral curves is to provide clearance as the lens moves across the flatter portions of the cornea with lateral gaze and blinking.
	www.revophth.com /index.asp?page=1_31.htm (1480 words)

	Atmospheric Reentry Encyclopedia Articles @ LaunchBase.org (Launch Base) (Site not responding. Last check: 2007-11-03)
		AMaRV had an entry mass of approximately 470 kg, a nose radius of 2.34 cm, a forward frustum half-angle of 10.4°, an inter-frustum radius of 14.6 cm, aft frustum half angle of 6°, and an axial length of 2.079 meters.
		This is roughly the time required for shock-wave-initiated chemical dissociation to approach chemical equilibrium in a shock layer for a 7.8 km/s entry into air during peak heat flux.
		The program works by preserving the original elemental abundances specified for the gas and varying the different molecular combinations of the elements through numerical iteration until the lowest possible Gibbs free energy is calculated (a Newton-Raphson method is the usual numerical scheme).
	www.launchbase.org /encyclopedia/Atmospheric_reentry (7509 words)

	Pacific Optometry Continuing Education Keratoconus Caroline
		In fitting a superior alignment lens for early keratoconus, a base curve is selected that is steep enough to land the lens at 3 and 9 o’clock along the horizontal meridian yet flat enough to avoid excessive impingement on the flatter superior cornea.
		The base curve should be steep enough to provide a slight central touch, shown by thinning of fluorescein, at the corneal apex and slight touch mid-peripherally at 3 and 9 o’clock along the horizontal meridian.
		A GP lens is selected with a base curve radius equal to the flat K and a diameter of approximately 9.0 to 9.5 mm.
	www.opt.pacificu.edu /ce/catalog/15167-AS/Keratoconus.html (11417 words)

	Review of Optometry November 1999 Contact Lenses
		To determine the base curve for a 9mm lens, subtract 0.50D from the average or mid-keratometry reading.
		In this instance, use a base curve equal to the mid- or average K. • Secondary curves (mm).
		The intermediate curve usually is 1mm flatter than the base curve; the peripheral curve is usually 3-5mm flatter than the base curve.
	www.revoptom.com /archive/issue/ro111f3.htm (2228 words)

	Xah: Special Plane Curves: Naming and Classification of Curves
		All the curves covered here are such that when you keep magnifying parts of the curve, it'll eventually looks like a line, unless you are magnifying a cusp point.
		It's a curve that, connects two given points such that it takes the same amount of time for a particle to slide from any point on the curve to the lower point, under ideal physical law.
		Isoptic of a given curve C and a given angle α is the locus of a point P such that P is the intersection of tangents of C that meets in angle α.
	www.xahlee.org /SpecialPlaneCurves_dir/Intro_dir/familyIndex.html (1001 words)

	Welcome to Optical Training Institute!
		It includes a discussion of vertex distance as well as the optical effects of the lacrimal lens which is formed between the front surface of the cornea and the back surface (base curve) of the lens.
		Methods and procedures for selecting base curve, diameter, optical zone width, peripheral curves, and thickness are covered to include the use of nomograms and diagnostic lenses.
		The use of the radiuscope is described and illustrated as it is used to verify the radius of curvature of a spherical surface.
	www.opticaltraining.com /html/exam_prep/ncle_contents_body.html (867 words)

	How To Read Prescriptions
		Base Curve or Series Base curve is the inside curvature of the lens and is usually given in millimeters of radius.
		Base Curve Base curves are measured in millimeters of radius.
		Secondary Curve This is the radius of curvature on the edge of the lens to smooth and thin the edge.
	www.wfvision.com /prescriptions.html (362 words)

	Contact Lens Fitting Self Assessment
		You place a diagnostic lens on the eye that you verify as -8.00 DS with a base curve of 7.50 mm.
		You select an initial base curve radius on flat K for the patient whose parameters are given below.
		You erroneously select an initial BCR based on the steep K for a patient whose parameters are given below.
	www.nova.edu /~chrisw/temp/rgp.sa2.html (868 words)

	Coil Winding Workshop
		Based on analysis of DELCOR output, Joe and I decided that only the outer(radius) near(nearest to the guiding strip), and outer(radius) far(farthest from the guiding strip) data are meaningful.
		The radius of the cylinder on which the base curve is wound is 1.9922520 inches, and the radius of the mandrel is 1.3779528 inches.
		The radius of curvature of corner-rounding is 0.000000.
	tdserver1.fnal.gov /cook/QandA.htm (3733 words)

	New Page 1
		This flatter radius of curvature is instrumental in creating the forces beneath the lens to facilitate the movement of corneal tissue.
		Adjacent to the base curve is a patented sigmoid-shaped curve that controls the amount of lens clearance across the central cornea.
		A shallower sigmoid in the return zone brings the base curve into closer apposition to the cornea, where a deeper sigmoid in the return zone results in greater apical clearance.
	www.boks.org.uk /newpage1.htm (2686 words)

	base curve - Contact lense information for those who choose not to wear glasses.
		Typical values are from 7.Base curve@Everything2.com In the fast paced and thrilling world of optics, the base curve is one of the The base curve is the curvature, in diopters, of the front of the lens.
		RELATED ENTRIES Base curve@Everything2.com In the fast paced and thrilling world of optics, the base curve is one of the The base curve is the curvature, in diopters, of the front of the lens.
		Base curve radius, or BCR, is a parameter of a contact lens.
	www.ispacs2005.com /base_curve.html (472 words)

	Encyclopedia :: encyclopedia : Optics (Site not responding. Last check: 2007-11-03)
		Geometric optics, sometimes called ray optics is the branch of optics that describes light propagation in terms of rays.
		Rays are bent at the interface between two dissimilar media, and may be curved in a medium in which the refractive index is a function of position.
		The ray in geometric optics is perpendicular to the wavefront in wave optics.
	www.hallencyclopedia.com /Optics (670 words)

	Welcome to Optical Training Institute!
		Corrected curve lenses, the rationale for the use of commonly recommended base curves, and the importance of the routine use of the “lens clock” will be presented.
		We’ll illustrate flourescein patterns of a spherical base curve on a spherical cornea, and spherical base curves on a toric cornea are presented.
		It is capable of measuring two curves, the steepest and the flattest, which are also referred to as the principal meridians.
	www.opticaltraining.com /html/continuing_ed/mail/cecs_mail_list_body.html (4751 words)

	contact lens fitting (Site not responding. Last check: 2007-11-03)
		base curve remains spherical a toric front surface correcting for the weight of 1 prism diopter base-down in lens is used to maintain correct orientation.
		the base curve of the triallens was 7.60 mm.
		second peripheral curve was 1.5 mm flatter than base curve and has the overall diameter of 12.0 mm.
	www.oncontactlens.com /contactlensfitting.htm (8431 words)

	curvature
		In fact, the evolute of a curve is the same as the envelope of its normal.
		The radial is a variation on the evolute: draw, from a fixed point, lines parallel to the radii of curvature, with the same length as the radii.
		The logarithmic spiral is the curve whose radial is the curve itself.
	www.2dcurves.com /derived/curvature.html (336 words)

	Medicals International / Issue #8/ (Site not responding. Last check: 2007-11-03)
		The patient is asked to direct his fixation down until the lower lid margin bisects the cornea horizontally.
		The curve thus imparted to the lower lid by the cornea is an indication of the degree of the cone.
		Base curves from 4.75mm to 8.00mm can be produced upon order.
	www.medicalsintl.com /issue8.html (2349 words)

	Calculus Animations with Mathcad
		A circle of radius r is rolling on a parametric "base" curve B(t).
		A spoke of length R is connected to the center of the circle, and a pencil attached to the end of the spoke traces a resulting curve.
		A physical interpretation of the resulting curve could be based on considering the 2-D picture to be a projection of a "thin" 3-D picture.
	www.math.odu.edu /cbii/calcanim (666 words)

	Tag Heuer Curve 5002 (Site not responding. Last check: 2007-11-03)
		Related phrases are toric contact lenses with base curve 86, called wild eye color changing contacts, comparing contact lenses, 1 day wear disposable contact lenses, and contact lense insertion.
		The values of BASE CURVE are typically 8.0, 8.1, 8.2, 8.3, 8.4 etc. Diameter (Dia) : Refers to the overall size...
		One base curve (8.6) and one diameter (14.5).
	strikelense.info (408 words)

	Contact Lens Spectrum
		Effective K incorporates both the central K and corneal diameter to assist in the appropriate selection of the base curve radius.
		In this situation, a flatter base curve will be necessary to provide the appropriate sagittal height.
		In both of these patients, the ultimate base curve required was significantly different from the base curve suggested by a manufacturer's traditional, keratometric-based fitting guide.
	www.clspectrum.com /article.aspx?article=12148 (532 words)

	Irvin-Rogers Brick & Block, LLC
		On an Inside Radius Curve, your base course will be the smallest radius in the wall, and must not be less than the minimum for the block system you're using.
		To build an outside radius curve, you first need to determine the radius of your top course to make sure it is not less than the required minimum for the product you are using.
		Attach a string and rotate it in a circle around the stake to mark the radius curve in the soil.
	www.rogersblock.com /rwallsres/radius.htm (985 words)

	[No title]
		This process is accelerated by the use of reverse geometry lens designs which have a steeper secondary curve to allow appropriate changes in the mid-peripheral cornea (i.e., "accelerated orthokeratology").
		The reverse curve is typically anywhere from two to eight diopters steeper than the base curve.
		The base curve is fitted flatter than ìKî in an effort to achieve an area of central bearing surrounded by a band of mid-peripheral tear pooling and approximately 1mm of lens movement with the blink.
	www.aaopt.org /userfiles/imagesPOSITION_PAPERS_CL/img_371933_Orthokeratology_Position_Paper.doc (2097 words)

	BCR - Wikipedia, the free encyclopedia
		BCR may stand for one of the following:
		Base curve radius, a parameter of a contact lens
		Belarusian Central Rada, a puppet government of Belarus under German occupation during World War II
	en.wikipedia.org /wiki/BCR (134 words)

	Conforma VFL 3 Quick Fit
		In order to offset this rapid flattening the apical radius (base curve at it's steepest point) must be fit considerably steeper than the flattest corneal meridian.
		In the example a base curve has been selected 2.50 diopters steeper than "K".
		This central clearance forms a significant plus tear lens between the base curve of the contact lens and the anterior surface of the cornea.
	www.conforma.com /vfl3FittingGuide.asp (318 words)

	AOCLE Living Library
		Soft lens fitting after PRK or LASIK generally employs the use of flatter base curves, to conform to the flatter corneal profile, as well as to avoid a tight-fitting lens.
		The 8.7 base curve is often used as the initial diagnostic test lens.
		Secondary curves may be 2-4 diopters steeper than the lens base curve radius.
	www.opt.indiana.edu /aocle/livlib/post_surgA.htm (2239 words)

	Count On (Site not responding. Last check: 2007-11-03)
		The curve we obtain of a fixed point on the circumference of a circle rolling on a line is called the Cycloid - but in general, as we shall see, there are many types of cycloid and we need to consider different cases of the base curve.
		These are the hypocyloids when the ratio of the base circle is 3, 4 and 5 of the rolling circle.
		Epicycles are curves where the centre of a circle moves around another circle and the locus of a point on the moving circle forms the curve.
	www.mathsyear2000.org /explorer/circles/cycloids (695 words)

	Program BEND, Module BnnC.for (Site not responding. Last check: 2007-11-03)
		SUBROUTINE STEP2 Construct the guiding strip (not developable) by twisting the rectifying developable about the base curve, which is held fixed.
		1100 Set the indices of the two points on the base curve at which the splining of the additional-twist of the rectifying developable starts and ends, to be equal to the indices of the first (namely, 1) and last points on the base curve, respectively.
		DO the additional-twist, moving the starting and ending of its splining towards each other until the new free edge of the strip does not bulge outside of the bounds given by its prescribed values at the first and last points on the base curve.
	tdserver1.fnal.gov /cook/PsuBc.htm (279 words)

	Archives of Ron's Weekly Thoughts as Posted on the Home page (Site not responding. Last check: 2007-11-03)
		Rays of lights cannot come to a single focus on the retina because of the different degrees of refraction in the various meridians of the eye.
		Base Curve: The radius of curvature of the central posterior surface of a contact lens.
		Peripheral curve: It is the outermost curve on the posterior lens surface.
	www.surgicaleyes.org /WandaGlossary.htm (851 words)

	David Thomas contact lenses Ltd
		Many early aspheric designs were based upon high eccentricity conic section optics and were somewhat limited in the maximal near power that could be produced.
		The lenses were dispensed in a power range of +3.00D to -7.75D, with base curves ranging from 7.20 to 8.30mm.
		This 7.50D base curve, 9.5mm lens diameter, Essential Series III GP multifocal lens has a small distance optic zone that allows for quicker translation into the intermediate and near optic zones.
	www.davidthomas.com /essential_3.htm (7850 words)

	SERIES (a Latin word f... - Online Information article about SERIES (a Latin word f...
		base and the tip, but dark brown for the rest of their length.
		radius may be zero as in the case of the series 1 +1!
		considerare, to look at closely, examine, generally taken to be from con-, and the base seen in sidus, sideris, a star, the word being supposed to be originally an astrological or astronomical term)
	encyclopedia.jrank.org /SCY_SHA/SERIES_a_Latin_word_from_serere.html (5488 words)

	[No title]
		Lens #1 BCR 7.50 mm, SCR 9.00, OAD 9.2 mm, OZD 8.0 mm, AEL 0.094.
		Lens #2 BCR 7.50 mm, SCR 9.00, OAD 10 mm, OZD 8.0 mm, AEL 0.175.
		Lens #3 BCR 7.50 mm, SCR 8.20, OAD 10 mm, OZD 8.0 mm, AEL 0.095.
	www.opt.indiana.edu /lowther/RGP.html (1179 words)

Try your search on: Qwika (all wikis)