To conserve power and reduce your electrical bill, you should shut down your computer or put it to sleep when not in use. But that's easier said than done if your Mac acts as a server for files, photos, music, or other resources.
Snow Leopard offers at least one solution to this problem: Wake on Demand. This is Apple's name for a new networking feature that lets a Snow Leopard Mac go to sleep while a networked base station continues to broadcast Bonjour messages about the services the sleeping computer offers. The base station essentially acts as a proxy for the slumbering Mac. Advertised Bonjour services includes file sharing, screen sharing, iTunes library sharing, and printer sharing among others.
The Eye-One Pro spectrophotometer is a nifty little device. It includes adapters for mounting to CRT or LCD monitors, and a transparent plastic guide for measuring reflective targets in scan mode.
When another computer on the network wants to use one of those Bonjour services, the base station sends a special signal over Ethernet or Wi-Fi to wake the computer in question, which then rouses itself and responds. Snow Leopard's improved speed in waking from sleep helps.
- Mac OS X Mountain Lion (10.8) is really a huge step forward and everyone is eager to get a copy of the final release. While waiting for the big day, you can do something else: check your current system, clean it, make a backup and be prepared for D-Day!
- One-Eye Kutkh - an exciting space adventure based on the fairy tales of the Far North. A single traveler on his way home crashes on a mysterious planet. To continue his journey, he'll have to get to the ninth heaven, deceive the Sun and the Moon and steal their space-boats.
- With the number of enhancements and refinements I can provide detailed summaries about with this new Mac OS X version, there is one service within Snow Leopard I found both potentially helpful and compelled to expound about, because it is a service not found in the previous, ground breaking version of Mac OS X, 10.5 Leopard.
To other computers, the sleeping Mac's shared services appear as regular Bonjour entries requiring no additional software. A Panther, Tiger, or Leopard system or Windows system with Bonjour installed can wake a Snow Leopard Mac. An awakened Mac goes back to sleep according to Energy Saver settings when it returns to an idle status.
What you'll need
Wake on Demand is a useful feature for Mac users who share resources between multiple machines, but it comes with some notable provisos. The first is the type of equipment you'll need.
Apple says you must have an AirPort Extreme Base Station (2007 or more recent model) or Time Capsule (2008 or more recent model) with the current 7.4.2 firmware installed.
Support for Wi-Fi comes with additional limitations. For starters, it appears only a relatively new Mac can be woken via a Wi-Fi connection. Older Mac models can be woken only when connected to the base station via Ethernet. (At this writing, Apple hasn't released a list of models that work over Wi-Fi, but, in testing with colleagues, I found only 2009 models offered the option. After this article was originally published, a reader tested his 2008 MacBook Pro [2.6 GHz Core 2 Duo], and found it capable as well. You can report other pre-2009 models in the comments.)
You can check whether your system supports Wake on Demand via Wi-Fi by opening System Profiler (go to Apple menu -> About This Mac, and click on More Info). In the Contents list at left, select AirPort (in the Network section). In the area under Interfaces, look for the text 'Wake on Wireless: Supported.' If it's not there, the option isn't available on that Mac.
Getting started
You enable Wake on Demand in the Energy Saver preference pane. On desktop machines, Snow Leopard shows a single pane; on laptops, the option is available in the Power Adapter tab. Laptops can't use this feature when powered by a battery. Additionally, laptops must either be open (not latched) or have an external display attached to be woken through this method.
For computers that can connect over either Wi-Fi or Ethernet, the checkbox is labeled Wake For Network Access. In my tests, this option was turned on by default in updated and new Snow Leopard Macs. Apple notes in a support document that some machines may have this option turned off after upgrading to Snow Leopard, in which case you'll need to turn it yourself.
Apple warns in its support note that your apparently somnolent computer may wake for just a moment to check in with the base station that's proxying Bonjour without activating its display, and then quickly go back to sleep.
You can disable Wake on Demand by unchecking the box. With the option turned off, your sleeping Mac will have its beauty sleep undisturbed and your base station won't advertise the Mac's Bonjour services.
How it works
In Leopard and earlier releases of Mac OS X, Apple offered a similarly labeled wake-on-Ethernet option that relied on the Magic Packet, a specially formulated data transmission that Ethernet adapters can be set to listen for in order to wake a computer in a standby mode. The Magic Packet option is a common feature in Ethernet cards and operating systems.
The flaw with the Magic Packet approach is that you had to use a special piece of software to wake a computer over Ethernet, and it didn't work over Wi-Fi. By switching to a Bonjour-triggered, base station-hosted method—which Apple calls Bonjour Sleep Proxy—Apple gives the feature broader reach. (Earlier this year, Macworld editor Dan Frakes reviewed a free program, WakeOnLan (), that handles the network voodoo for Magic Packets. In addition to Apple's new Wake on Demand option, I've confirmed that WakeOnLan still works with Snow Leopard systems connected over Ethernet.)
The technology behind waking a computer over Wi-Fi is more complicated. Wi-Fi radios typically shut down when a computer isn't active; however, some Wi-Fi-enabled devices employ a standby scanning mode that wakes a radio for extremely brief periods of time to scan for incoming traffic. This mode typically takes advantage of WMM Power Save, a standard designed to reduce power usage by Wi-fi-capable cellular handsets and portable devices while they're not transmitting.
It's possible that Apple using technology similar to WMM Power Save to give a Mac's Wi-Fi adapter just enough power to monitor for the right kind of alert, and wake the system. (After this article was originally published, Apple said via e-mail that it is not using WMM Power Save, but provided no additional details.)
If Apple has taken an open approach to waking a Mac over Wi-Fi—that includes the use of Bonjour which Apple invented but doesn't restrict the use of—it's good news for Mac users. In the coming weeks we may see programs developed that allow other software, servers, or routers to wake the slumbering Snow Leopard.
[Glenn Fleishman is the author of Take Control of Your 802.11n AirPort Network (www.takecontrolbooks.com ), and a regular Macworld contributor.]
[Updated August 28th, 2009 at 2:36 PM to reflect newly released details about Wake on Demand and correspondence from Apple.]
There are two different kinds of advanced age-related macular degeneration (AMD): dry AMD and wet AMD.1 In wet AMD, new abnormal blood vessels grow underneath the retina in a process called choroidal neovascularization (called CNV). Patients with myopic macular degeneration, or MMD, can also develop abnormal leaky blood vessels, under the retina, however the disease process is not age-related as in wet AMD.2 When they leak or bleed, the retina may be damaged, causing significant rapid vision loss. By the time wet AMD is diagnosed, the disease is already considered advanced or late stage. While treatment cannot reverse damage that has been done, treatment is available to help slow or even prevent further progression.
What are intravitreal injections?
One of the treatments for wet AMD and MMD with CNV involves an injection of medicine into the vitreous gel, located in the back of the eye near the retina; this procedure is called an intravitreal injection, and is typically performed by a retina specialist. An injection into the eye allows medicine to be delivered closer to the area of disease and also minimize the risk of side effects to the rest of your body.
One Eye Masquerade Mask
What is anti-VEGF?
A protein called vascular endothelial growth factor (VEGF) is produced in high levels in the eye, and this molecule signals the growth of new abnormal leaky blood vessels.1 In order to combat this process, anti-VEGF drugs may be injected into the eye to inhibit the VEGF molecule, thereby preventing the formation of new leaky blood vessels. There are several different kinds of anti-VEGF medications, and the dosage and injection schedule can vary depending on disease severity and treatment response.
Eye injection anxiety
Getting an injection anywhere can be an unnerving experience, especially in the eye. It's completely normal to have some anxiety about the treatment, but the more you know about the process, the less nervous you might be.
Establishing a treatment plan
Once it's been clinically established that you have wet AMD or MMD with CNV, your eye doctor will talk with you about your condition and which medication might be best for you, as well as what dosing schedule you will be started on. Once he or she evaluates how your eye responds to the treatment, the medicine and dosing interval may change.
What to expect when getting eye injections
- First, the doctor will clean your eye and eyelid with a yellow iodine solution, and then numb your eye with drops, a gel, or even a numbing shot.
- After your eyes are numbed, they will use an eyelid holder to keep your eyelids open during the injection.
- The place of injection will be measured; usually the outer lower part of the eye, near your ear.3
- You'll be asked to look up, and the injection will take place.
The entire injection process usually takes just a few minutes once the eye is numbed. You might feel some pressure or nothing at all, but you should not feel significant pain. You might see some wavy lines or floaters as the medicine is distributed around the eye.3
Aftercare for eye injections
Once the injection is finished, the doctor will look at your eye and clean around it with an eyewash solution.
You might have some soreness or discomfort in the eye, along with foggy vision or floaters for a day or two. If you do have soreness, this is easily taken care of with over-the-counter medication; if you experience no relief with this, call your doctor. Gently holding a clean, cool washcloth to your closed eye for 10 minutes at a time might also help.3
Complications
As with any medical procedure, sometimes side effects or complications may arise from eye injections.
Common side effects
Common side effects can include:4
- Temporary blurry vision
- Eye soreness/irritation
- Mild eye redness
- Temporary increase in eye pressure
Serious complications
Serious complications are rare, but if present, can be vision threatening and warrant immediate attention by your doctor. These complications may include:
- Eye infection (called endophthalmitis)
- Stroke (with certain medicines)
Talk with your doctor about the signs or symptoms of serious complications, and call your doctor if you experience anything out of the ordinary or pain that does not go away.
Other complications
Sometimes during the injection, the needle may hit a surface blood vessel and break it, causing the white of the eye to look red and bloody. This can last several weeks, but is generally painless, will not affect your vision, and often resolves on its own. If you are experiencing increasing pain or changes in vision, call your doctor.
Adjusting to the process
One-eye Mac Os Update
As with anything new, each time you go for an injection it will hopefully become a little less nerve-wracking as you learn what to expect and what your 'normal' is. Many people will find that their vision becomes more stable after the injections begin, and some might find even a slight improvement. If you have any questions about the process, don't hesitate to talk with your doctor.