 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Medical Forum / General / Vision / November 2006double image through eyeglass
Hi, I got my new pair of eyeglasses, but my left eye see double images slightly off each other. for example, look at 2 neon horizontal line lights (one about 1 inch above the other) especially in green color, from a distance about 15feet, my left eye through eyeglasses will see "3" lines of neon lights, the "ghost image" is higher than the 2 real image, if I raise my head backward such that I see the neon lights through lower part of my eyeglasses, the "ghost image" will disappear and I see clearly. if I walk closer to about a few feet, double image will disappear, this is left eye only, same with and without my right eye open. I wonder is this due to the not so good prescription of the eyeglasses? what could cause such problem from eyeglasses optically? or is it my left eye that's the cause? (I can't tell since if I look at things with naked left eye everything so burry hard to tell if there's a slightly offset ghost image) another pair of glasses with similar prescription except axis 8 degrees different has the same problem. thanks a lot! ghost images as you describe are pretty normal, esp. from strong emitters like fluor. tubes. The blur is not normal, and means something is wrong with your eye or the lens. AR coating will help minimize ghosting. Since the ghosts merge with the main image in the lower part, that means your lens might also have some unwanted vertical prism. Removing the prism will help the ghosts merge closer to the part of the lens you mostly use (usually a bit above center). w.stacy, o.d. >Hi, I got my new pair of eyeglasses, but my left eye see double images >slightly off each other. for example, look at 2 neon horizontal line [quoted text clipped - 17 lines] > > thanks for the reply, the "ghost" image I don't mean the ghost image caused by multiple reflection on the lens surface which as you said can be reduced by AR coding, I see those but those are lower than the real image and pretty far apart, the ghost image I mentioned is just slightly (like shadow) above the real image which I can't understand the mechanism by light tracing through the lens. the "unwanted vertical prism" sounds interesting but this zeiss lens is made with prescription for nearsightness only without any "prism" spec, do you mean they can make different lens while maintain the same prescription? > ghost images as you describe are pretty normal, esp. from strong > emitters like fluor. tubes. The blur is not normal, and means something [quoted text clipped - 27 lines] > > > > That's a pretty confusing reply. I'm not convinced that your original post was correct, and that they are indeed ghost images, which are caused by internal reflections (light refracted through the front surface, reflected off the back surface back toward the front surface, then once again reflected back toward the eye off the front surface). You can differentiate these ghost images from other sorts of monocular diplopia by the fact that if the lens has any power at all, the separation between the primary image and the ghost image will change as you vary the part of the lens through which you are viewing, exactly as you described in the first post. No other kind of monocular diplopia behaves like that. Prism simply shifts the ghost image away from the base of the prism, but the separation will still change as you move your line of fixation. If on the other hand the lens has no refractive power, then the ghost will be on the main image (not visible to you), or displaced by the amount of prism, and will not vary as you use different parts of the lens. w.stacy, o.d. >thanks for the reply, > [quoted text clipped - 49 lines] > > I meant "I'm not convinced that your original post was incorrect". Tripped up by the double negative once again... w.stacy, o.d. My confusing reply was made worse by my attempted correction. Here, let me fix it one more time: > I'm not convinced that your original post was incorrect, and I do > think that they are indeed probably ghost images, which are caused by [quoted text clipped - 14 lines] > > w.stacy, o.d. oh and yes, they can grind prism independently of the spherocylindrical Rx, and it can be as ordered (prescribed) or accidental (inadvertent). If it's enough, you can get binocular diplopia and other binocularity symptoms from it. I'm no eye doc, but this sounds similar to how my astigmatism manifests itself uncorrected. Rather than smearing, I get fairly distinct doubling. Maybe your prescription isn't fully correcting. > Hi, I got my new pair of eyeglasses, but my left eye see double images > slightly off each other. for example, look at 2 neon horizontal line [quoted text clipped - 16 lines] > > thanks a lot! -- I found the official name for this: Monocular diplopia, the question is, is it caused by my eyeglass or my eye itself? if it's my eye, I would imagine I will see the same double when looking through lower half of my eyeglass, but no double in that case... |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.