Why does my eye jump or twitch?
Sometimes part of your eyelid may twitch for several minutes or hours. Muscle spasms in the eyelid cause muscle twitches. The technical term is blepharospasm. These twitches can be related to emotional stress or physical eyestrain. For example, staring at a computer all day can cause the eyes to twitch. It may also be brought on by stress or strain such as overtiredness, anxiety or not enough sleep or too much caffeine. It may even have triggers like bright light or smoking.
Occasional twitching of the eyelid is usually transitory and disappears by itself. It does not indicate a serious problem unless it persists or extends to other parts of the face. To prevent the problem of twitching you need to reduce the stress in your life. You may take a long bath,try yoga or a massage to relax your muscles. Avoid too much fatigue. Make sure you get enough rest and at least eight hours of sleep. You may switch to decaffeinated tea or coffee as too much caffeine may keep some people awake at nights. If the problem persists be sure to consult your eye specialist.
Is it dangerous to look
directly at the sun?
Looking at the sun occasionally does not usually harm the eyes. However staring at the sun for several minutes can damage cells in the visual system that allows us to see fine detail. The lenses of your eye act as magnifiers and the rays of the sun are focused on the retina of your eyes and can burn them. This kind of injury is called solar retinopathy and can cause a blind spot in the centre of your visual field. Your retina is not sensitive to pain and you will not feel it happening. A retinal burn is permanent and irreversible.
Prolonged exposure to sunlight can cause dizziness, discomfort, strain, a temporary reduction in vision and pain. However, the most important danger to our eyes is the exposure to the invisible ultraviolet or UV light. The danger is not only on bright, sunny days as the majority of UV light can penetrate the cloud cover. Over exposure to sunlight can cause eye disorders like cataract and may also damage the cornea and retina.
How are sunshades useful?
Everyone, especially individuals who spend time in the sun for extended periods, is at risk for eye damage from the sun year-round. It is important to protect your eyes just as you apply sunscreen to protect your skin. In fact the cornea is 300 times more sensitive to sunlight than your skin. Sunlight exposure increases about 10 per cent for every 3,000 feet of elevation gain. It is most severe between 10 am and 2 pm. Water reflects 20% and sand 35% of the sunlight.
Everyone needs eye protection, even children. They have wider pupils and more sensitive ocular tissues and may be more affected by sunlight than adults. Sunglasses must fit well to be effective. They should not slide down your nose and should be as close to your face as possible while providing enough space for your eyelashes to move without touching the lenses. Wrap around models are also available.
Sunglasses that absorb at least 99-100% of both UV-A and UV -B rays are advisable.
Green, brown and grey tints are best for bright sunlight. Warm colours like orange, brown, yellow and red improve depth and detail perception. Blue is better suited to moderately bright light such as hazy sunshine. Yellow and orange are best for low-light situations like on trails in the forests.
Photochromatic lenses adjust to the amount of light present. They are good for outdoor activities and for moving from indoor to outdoor light conditions. They can be used in prescription sunshades. Polarized lenses are available in many colours and darkness. Polarization reduces glare off reflective surfaces like roads, cars and buildings. There is an increase in visual acuity and polarized lenses reduce eye fatigue and discomfort caused by glare.
Ask your optometrist to advise you on the different types of lenses and tints recommended for your particular needs.
